AROMATIZATION STUDIES IN THE NAPHTHALENE SERIES

Citation preview

AROMATIZATION STUDIES IN THE NAPHTHALENE SERIES

A D i s s e r t a t i o n i n C hem istry P r e s e n te d to th e F a c u lty o f th e G raduate School o f th e U n iv e r s ity o f P e n n sy lv a n ia in P a r t i a l F u lf i llm e n t o f th e R equirem ents f o r th e D egree o f D octor o f P h ilo so p h y

uperviefor

C h a i r m a n o f G ro u p C o m m i t t e e

A rth u r Irw in Low ell P h ilad elp h ia,

P en n sy lv an ia

1951

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.

ACKNOWLEDGEMENT

T h i s i n v e s t i g a t i o n w as u n d e r t a k e n a t t h e s u g g e s tio n o f Dr.

E.

C. H o r n i n g .

w ishes to ta k e t h i s o p p o r tu n ity to

The a u t h o r express h is

th a n k s t o Dr. H o rn in g f o r h i s v a l u a b l e a d v ic e and a s s i s t a n c e d u r i n g t h e c o u r s e o f t h i s work. F e l l o w s h i p s from t h e R e s e a r c h C o r p o r a t io n and B r i s t o l L a b o r a t o r i e s a r e g r a t e f u l l y acknow ledged.

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.

TABLE OF CONTENTS

Page In tro d u ctio n

. . . .

....................................................................

1

D iscussion:

D e h y d r o g e n a t i o n ...............................................

3

D isc u ssio n of E xperim ental D iscussion:

....................................................

S p e c t r a ..........................................

.....................

15 53

E x p e r i m e n t a l ........................................................................................ 64 S u m m a r y .........................................................................................................1 1 5 B i b l i o g r a p h y .............................................................................................. 11 6 B i o g r a p h y ..................................................................................

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.

120

1

In tro d u ctio n

D uring th e p a s t t h i r t y

y e a r s numerous exam ples o f

t h e d e h y d r o g e n a tio n o f an a l i c y c l l c compound h a v e b e e n r e p o r t e d .

c o m p o u n d t o an a r o m a t i c

Many t y p e s o f a l i c y c l l c

compounds u n d e r g o d e h y d r o g e n a t i o n u n d e r t h e a p p r o p r i a t e conditions,

and t h i s g e n e r a l method h a s b e e n u s e d a s a

r o u t e t o many a r o m a t i c c o m p o u n d s . fo r s tru c tu ra l purposes,

i.

e.

to

o f n a t u r a l l y o c c u r r i n g compounds. years i t

h a s come i n t o

m ethod to

Its

c h ie f u se h as been

e lu c id a te th e

stru ctu re

W ith in t h e p a s t few

In c re a s in g use as a p r e p a ra tiv e

s y n t h e s i z e c o m p o u n d s i n t h e i r own r i g h t o r a s a

supplem ent to i t s

use in s tr u c tu r a l d e te rm in a tio n s.

The work t o be d e s c r i b e d i n t h i s d i s s e r t a t i o n concerns th e

sy n th esis of c e rta in s u b s titu te d 3 ,4 -d ih y d ro -

n a p h th a le n e s and t h e i r c o n v e rs io n to t h e r e l a t e d n a p h th a le n e s by c a t a l y t i c d e h y d r o g e n a tio n . A s e r i e s o f 1 , 2 ,3 , 4 - t e t r a h y d r o n a p h t h a l e n e o were a ls o p r e p a r e d by t h e r e d u c t i o n o f t h e c o r r e s p o n d i n g 3 , 4 - d i h y d r o n aphthalenes. S ince s e v e ra l in g in type,

s e r i e s o f compounds w e r e p r e p a r e d v a r y ­

number and l o c a t i o n o f s u b s t i t u e n t s ,

degree of s a tu ra tio n , of these fa c to rs

th e o p p o rtu n ity to

and

stu d y th e

effect

on t h e a b s o r p t i o n o f u l t r a v i o l e t l i g h t

was t a k e n .

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.

2

T h e s y n t h e s i s o f s e v e r a l new 1 - n a p h t h o l s t h r o u g h a ro m atlz atio n of the a p p ro p ria te ly w as a l s o

su b stitu ted 1-te tralo n es

attem pted.

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.

3

D iscussion:

D ehydrogenation

The c o n v e r s i o n o f an a l i c y c l l c

com pound a t t h e

same f o r m a l l e v e l o f s a t u r a t i o n a s an a r o m a t i c compound, a t a h ig h er le v e l,

or

t o a n a r o m a t i c compoun d I s c a l l e d

aro m atizatlo n . A d e f i n i t i o n o f "aro m atic c h a ra c te r"

Is b ased upon

t h e n u m b e r o f p r o p e r t i e s w h i c h a r e common t o a r o m a t i c s t r u c t u r e s and whose p o s s e s s i o n g iv e s t h e m o le c u le t h i s q u ality . ic ity ",

T h e s e p r o p e r t i e s may b e u s e d t o d e f i n e " a r o m a t o r t h e y may b e r e g a r d e d a s t h e m a n i f e s t a t i o n s o f

t h e n a t u r e o f a s t r u c t u r e which in v o l v e s a r i n g th e benzene ty p e . fundam ental i s

Of t h e s e p r o p e r t i e s

the unusual s t a b i l i t y

a s compared w ith th e co n sid e ratio n s.

sta b ility

one o f t h e m ost

of th e r in g

system

in the l i g h t of a lic y c llc

Thus b en zen e h a s l e s s

th an the h y p o th e tic a l a lic y c llc

system o f

te n d e n c y t o decompose

c y c lo h e x a trie n e w ith non-

i n t e r a c t i n g double bonds.

T his unusual Im m u ta b ility i s

re fle c te d q u a lita tiv e ly in

t h e t h e r m a l d a t a f o r t h e com­

b u s t i o n and h y d r o g e n a tio n o f b en zen e and f o r t h e d eh y d ro ­ g e n a t i o n o f d i h y d r o b e n z e n e ( w hen c o m p a r e d w i t h t h e c a l c u l a t e d "alicy cllc"

v alu es).

T h e re a r e num erous m eth ods which can be u s e d t o a licy cllc

compounds t o a r o m a t i c compounds.

p e n d e n t upon t h e

convert

They a r e d e ­

s tru c tu re of the a lic y c llc p recu rso r.

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.

4

Is o m e riz a tio n has been u sed to of a lic y c llc

stru ctu res

e f f e c t th e conversion

to t h e i r aro m atic Iso m ers.

m ethod 1 b d e p e n d e n t upon t h e r e l a t i v e tw o f o r m s ,

sta b ility

T his

of the

a n d on t h e e a s e o f t r a n s i t i o n f ro m o n e form t o

the o th er.

Th e a r o m a t i c f o r m i s u s u a l l y m o r e s t a b l e .

ease of tra n s itio n

Th e

from one fo rm to a n o t h e r u s u a l l y d e t e r ­

m ines t h e p o s s i b i l i t y o f s e p a r a t e e x i s t e n c e o f t h e a l i c y c l l c m olecule, In

e s p e c i a l l y i f t h e a r o m a t i c m o l e c u l e i s more s t a b l e .

some c a s e s w h e r e a n a l i c y c l l c

product,

its

aro m atic Isom er I s

co m p o u n d i s obtained;

th e in ten d ed

th e conditions

o f th e r e a c tio n induce is o m e r iz a tio n .

In o th e r cases the

alicy cllc

e x i s t e n c e and

c o m p o u n d s do h a v e a s e p a r a t e

is o m e ric a r o m a tiz a tlo n only a w a its

su itab le

co n d itio n s.

A lic y c llc - a ro m a tic is o m e riz a tio n u s u a lly can occur t h r o u g h two g e n e r a l m e t h o d s :

(l)

carbon-to -carbo n f is s io n

and ( 2 ) hydrogen r e d i s t r i b u t i o n . C arbon-to-carbon f i s s i o n u s u a lly o ccu rs in th e tr a n s ­ fo rm a tio n o f s tr u c tu r e s w ith b rid g ed r in g s to th e aro m atic Isom er, cases,

and r in g c o n t r a c t i o n and is o m e r i z a t i o n i n o t h e r t o m e n tio n a few ex a m p le s.

An a l i c y c l l c

co m po un d c a n d i f f e r f r o m i t s

aro m atic

I s o m e r i n t h e a rra n g e m e n t o f h y d ro g en atom s a l o n e . izatio n

Isom er­

In th e s e c a se s r e q u ir e s only th e r e d i s t r i b u t i o n

t h e h y d r o g e n ato m s so t h a t t h e r i n g o r r i n g s a c q u i r e ,

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.

of

5

t h r o u g h t h i s p r o c e s s , an amount o f u n s a t u r a t i o n c o r r e s p o n d I i n g to t h e K ekule ty p e o f s t r u c t u r e . A cids and b a s e s , hydrogenation c a ta ly s ts , been used to

and h e a t have

e ffe c t Iso m erizatio n o f a lic y c llc

D ehydrogenation i s to

d ehydrohalogenatlon,

c o n v e r t an a l i c y c l l c

compounds.

a n o t h e r m ethod w hich c a n be u s e d compoun d t o

an a r o m a t i c compound.

The work d e s c r i b e d I n t h i s d i s s e r t a t i o n c o n c e r n s an i n ­ v estig a tio n

of th e

sy n th esis of c e rta in a lic y c llc

com­

p o u n d s a n d t h e i r c o n v e r s i o n t o a r o m a t i c compounds by t h e rem oval o f hydrogen. D uring th e p a s t th r e e d ecades, been u se d m ainly f o r p ro d u cts.

stru ctu ral

dehydrogenation has

stu d ie s of organic n a tu ra l

N o ta b le e a r l y exam ples o f i t s

use in

elu cid atin g

s t r u c t u r e a re in th e p o ly te rp e n e r e s e a rc h e s of R uzicka ( l) and th e d e h y d ro g e n a tio n o f c h o l e s t e r o l and c h o l i c a c i d w h i c h p l a y e d an I m p o r t a n t p a r t i n d e t e r m i n i n g t h e of th e

ste ro ls

in v estig atio n s

(2).

H aw orth and R i c h a r d s o n ( 3 ) ,

stru c tu re In t h e i r

concerning th e s tr u c tu r e of p o d o p h y llo to x ln ,

co n v erted podophyllotoxln in to

a com pound c o n t a i n i n g t h e

1 -p h en y ln ap h th alen e nucleus ( I ) .

They a l s o p r e p a r e d I by

an unam biguous m ethod th r o u g h d e h y d r o g e n a tio n o f t h e lacto n e I I .

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.

6

OcH, O r^^irO C i

OCH3 CH30

ISOM. v o ------------ > CHxOH

PKROPopo PHYUIN

popopHyuuoroxiM

I

OCH,

oc H3 ch^o^

\ ,

oc^

p d - b la c k

3

oO

ppQLftCK

X

DEHYDRO PNHYDROPlcROPoDOPHYLLlU

The u s e o f o r d i n a r y d e g r a d a t l v e m ethods t o th e is

e sta b lish

s t r u c t u r e of h ig h m o le c u la r w eight a l i c y c l l c d iffic u lt

a n d t i m e c o n s u m i n g i n many c a s e s .

compounds The con­

v e r s i o n o f t h e s e compounds i n t o r e l a t e d a r o m a t i c compounds by d e h y d ro g e n a tio n answ ers th e q u e s tio n of r i n g p o sitio n ,

s iz e and

and p o s itio n o f s u b s titu e n ts .

D e h y d r o g e n a t l o n h a s come i n t o

i n c r e a s i n g prom inence

d u r i n g t h e p a s t f e w y e a r s as, a s y n t h e t i c r o u t e t o

aro m atic

compounds.

T h is m ethod i s

u s e f u l i n man y c a s e s i n

t u r a l work,

s i n c e t h e p r o d u c t o f an u n am biguous s y n t h e t i c

p r o c e d u r e may b e c o m p a r e d w i t h t h a t d eg rad atlv e procedure.

stru c­

o b ta in e d from a

Bergmann a n d c o w o r k e r s

(4)

sy n th e­

s i z e d a r o m a t i c r e f e r e n c e co m p o u n d s b y d e h y d r o g e n a t l o n d u r i n g

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.

7

th e ir in v e stig a tio n in to

t h e m echanism o f t h e W agner-

Jauregg re a c tio n . T here a re t h r e e r e a g e n ts in p r e f e r r e d u se a t th e p r e s e n t tim e,

su lfu r,

selenium ,

and t h e p la tin u m m e t a l s .

T he i m p o r t a n c e o f s u l f u r i n d e h y d r o g e n a t l o n was f i r s t r e c o g n i z e d “by R u z l c k a ( 1 ) . D iels

(5).

also used.

S e l e n i u m was i n t r o d u c e d b y

P la tin u m and p a lla d iu m i n v a r io u s form s a r e T he u s e o f p a l l a d i u m d e p o s i t e d on f i n e l y

d iv id e d carbon i s

fin d in g in c re a sin g favor.

N ot v e r y much i s know n a b o u t t h e r e a c t i o n m e c h a n i s m o f deh ydrogenatlon.

Any s t u d y o f t h e m e c h a n i s m o f d e h y d r o ­

g e n a tio n w ith th e s e v e ra l r e a g e n ts used w i l l have to c o n c e rn i t s e l f w ith accom panying th e rm a l e f f e c t s

sin c e

dehydrogenations are u s u a lly c a r r ie d out a t r e l a t i v e l y high tem p eratu res.

The p l a t i n u m m e t a l s a r e u s e d a s h y d r o ­

g en atio n c a ta ly s ts ;

th ey have th e a b i l i t y to t r a n s f e r

h y d r o g e n from one o r g a n i c m o le c u le t o a n o t h e r , a d d a n d / o r remove h y d r o g e n fro m c e r t a i n

stru ctu res,

o r w ith o u t th e a id of m o le c u la r hydrogen. h a s been u t i l i z e d

o r sim ply to w ith

T his p ro p e rty

fo r dehydrogenatlon p u rp o ses.

S elenium

a n d s u l f u r a c t on t h e a l i c y c l l c m o l e c u l e i n a w a y t h a t th e hydrogen i s su lfid e,

e lim in a te d a s hydrogen s e le n ld e o r hydrogen

a s t h e c a s e may b e .

Selenium h a s been r e p o r t e d

to have very s li g h t a c t i v i t y as a hydrogenation b u t a c c o rd in g to P l a t t n e r

(6 ),

cataly st,

c a ta ly tic dehydrogenations

a r e p r o b a b l y b a s e d on f u n d a m e n t a l l y d i f f e r e n t r e a c t i o n s

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.

8

th a n a r e d e h y d ro g e n a tio n s w ith selenium and s u l f u r . r e s p e c t to f in a l r e s u l t s ,

th e d is s im ila r itie s

W ith

a re not very

I m p o r t a n t a n d seem t o b e f o r t h e m o s t p a r t d u e t o t h e d i f f e r e n t r e a c t i o n te m p e r a tu r e s and le n g t h o f tim e a compound i s

s u b je c te d to d e h y d ro g e n a tio n .

T h e com pound t o b e d e h y d r o g e n a t e d i s u s u a l l y h e a t e d w ith s u lf u r a t 200- 220°;

th e

e v o lu tio n o f hydrogen s u lf id e

b e i n g c o m p le te w i t h i n a few h o u r s . A selenium d e h y d ro g e n a tio n i s u s u a l l y c a r r i e d o u t a t 250-280°;

lo n g r e a c tio n

t i m e s b e i n g em ployed (20 t o 100

hours). C a ta ly tic dehydrogenations a re c a r r ie d out in a v a r i e t y o f ways. and c a ta ly s t p o in t is

H e a tin g an i n t i m a t e m ix tu re o f m a t e r i a l

at th e b o ilin g p o in t

(providing th e b o ilin g

s u f f i c i e n t l y h ig h enough t o

can be u sed .

e f f e c t dehydrogenatlon)

A g i t a t i o n o f a m i x t u r e o f compound an d

c a t a l y s t a t a high tem p eratu re in th e case of v ery h ig h b o i l i n g compounds w i l l u s u a l l y

su ffice.

s o lv e n t in c a t a l y t i c dehydrogenatlon i s

The u s e o f a a d v a n ta g e o u s where

t h e a r o m a tiz e d m a t e r i a l and s o lv e n t can be s e p a r a t e d .

T he

te m p e r a tu re s and r e a c t i o n tim e s v a ry i n th e c a s e o f c a t a l y t i c dehydrogenations. 550°.

In g eneral,

At t h i s p o i n t i t

above 350° i n a l l

th e y a r e c a r r i e d o u t below

may b e n o t e d t h a t u s e o f t e m p e r a t u r e s

t h r e e m ethods i n c r e a s e t h e p o s s i b i l i t y

o f th e occurrence of sid e r e a c tio n s . N o r m al d e h y d r o g e n a t i o n s a r e t h o s e i n w h i c h no

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.

9

cleavage,

rearrangem ent,

carb o n bonds o c c u rs .

o r f o r m a t i o n o f new c a r b o n - t o -

A l a r g e number o f s u b s t i t u t e d

cyclo-

hexanes, h ydrogenated n ap h th a le n e s and p h e n a n th re n e s,

and

hy d ro g en ated d e r iv a tiv e s of h ig h e r condensed aro m atic sy stem s can be r e a d i l y d e h y d ro g e n a te d t o t h e i r p a r e n t a r o m a t i c compounds.

Exam ples a r e t h e d e h y d r o g e n a t i o n o f

d e c a l i n to n a p h th a le n e and t h e c o n v e r s io n o f h e x a h y d ro flu o re n e to flu o re n e .

I n g e n e r a l t h e c a t a l y t i c m ethod

i s p re fe rre d because of i t s

s i m p l i c i t y and c l e a n l i n e s s .

T h e r e a r e some d e h y d r o g e n a t i o n s w h i c h a r e a c c o m p a n i e d by a change i n t h e c a rb o n s k e l e t o n .

An i n t e r e s t i n g

betw een t h e a c t i o n o f t h e c a t a l y t i c m ethod and t h a t

d ifferen ce of

s u l f u r o r s e le n iu m h a s b e e n n o t e d i n t h e c a s e o f compounds c o n ta in in g q u a r te r n a r y m ethyl groups.

S ince th e p o s itio n

c o rre s p o n d in g to a q u a te r n a ry m ethyl group does n o t in th e arom atic c o u n te r p a r t,

ex ist

th e m eth y l.g ro u p u s u a ll y

e l i m i n a t e d i n most d e h y d r o g e n a t i o n s ; m ig ra te s to an a d ja c e n t p o s i t i o n .

in

is

some c a s e s i t

In g e n e ra l,

the

t e m p e r a t u r e s n e c e s s a r y f o r d e h y d r o g e n a t l o n o f compounds c o n t a i n i n g q u a t e r n a r y m e th y l g r o u p s by s u l f u r a n d s e le n iu m a r e I n c r e a s e d on ly s l i g h t l y above th o s e r e q u i r e d f o r norm al d e h y d ro g e n a tio n s, in

but c a t a l y t i c dehydrogenation

s u c h c a s e s r e q u i r e s a much h i g h e r t e m p e r a t u r e t h a n

no rm al.

I n most c a s e s ,

q u a te rn a ry m ethyl g roups a r e th e

o n ly c a r b o n - c o n t a i n i n g g ro u p s w hich s p l i t

out or m igrate

d u rin g dehydrogenatlon.

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.

10

An i n t e r m o l e c u l a r t r a n s f e r o f h y d r o g e n o c c u r s I n many c a t a l y t i c d ehy drogenations. o rtlo n atio n ,

resu lts

T his e f f e c t ,

c a lle d disp ro p -

in th e conversion of u n s a tu r a te d

-compounds t o m i x t u r e s o f a r o m a t i c a n d c o m p l e t e l y s a t u r a t e d compounds.

I n t h i s way c y c l o h e x a d i e n e i s

m ix tu re o f benzene and c y c lo h e x a n e . is

converted in to

D ih y d ro n ap h th alen e

a m ixture of t e t r a l i n

in th e p resen ce of p latinum b lack .

co n v erted to a

and n a p h th a le n e

The f a c t

th a t d is­

p ro p o rtio n o ccu rs does not p re c lu d e th e p o s s i b i l i t y com plete d e h y d ro g e n a tio n ta k in g p la c e .

Som etim es d e h y d r o ­

g e n a t l o n t a k e s p l a c e i n a two s t e p r e a c t i o n

T e tralin is

of

(7).

e a s i l y dehydrogenated a t 185° w ith a

palladium -carbon c a ta ly s t.

The f o l l o w i n g

eq uilibrium

ex ists:

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.

11

The e q u i l i b r i u m i s or ag itatio n

f a r to

the l e f t ,

but eb u llu tio n

of th e m ix tu re d is lo d g e s th e hydrogen adsorbed

by th e

cataly st

easily

(7).

and th e d e h y d ro g e n a tlo n ta k e s p la c e

T h e r e a r e some g e n e r a l t h a t have been n o ted .

e f f e c t s on f u n c t i o n a l g r o u p s

The f i r s t

sy ste m a tic stu d y of th e

i n f l u e n c e o f f u n c t i o n a l g ro u p s and s u b s t i t u e n t s

on t h e

c o u r s e o f d e h y d r o g e n a t l o n was c a r r i e d o u t b y Newman a n d cow orkers ria te ly

(8 ,9 ,1 0 ).

C a ta ly tic dehydrogenations of approp­

s u b s t i t u t e d te tra h y d ro n a p h th a le n e s w ith a p a lla d iu m -

c a r b o n c a t a l y s t w ere s t u d i e d .

COOCH, COCH

CHo 0H, -CH 0 CCOCH.

CHoCOCH

The r e s u l t s su b stitu en ts

CHoCHoCOCH' in d ic a te d th a t th e lo c a tio n of th e

in r e la tio n

to th e hydrogenated r in g d e t e r

m ined th e e x t e n t o f d e h y d ro g e n a tlo n .

Th e f a t e o f t h e

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.

12

s u b s t i t u e n t d e p e n d e d on I t s

n a t u r e and i t s

An e x a m p l e o f t h e i n f o r m a t i o n o b t a i n e d i s

lo catio n . as fo llo w s.

The d e h y d r o g e n a t l o n o f compounds c o n t a i n i n g t h e k e t o n l c g r o u p (-COCH 3 ) r e s u l t e d i n g r a d e d d i f f e r e n c e s . com p o u n d b e a r i n g t h i s

group a tta c h e d to th e b e ta p o s it i o n

o f t h e a r o m a t i c r i n g was d e h y d r o g e n a t e d , g r o u p was r e d u c e d t o a m e t h y l e n e g r o u p ; amount o f t h e In c o n tra st,

When t h e

th e carbonyl only a sm all

c o r r e s p o n d i n g n a p h t h y l k e t o n e was o b t a i n e d . t h e k e t o n e f u n c t i o n w as n o t a t t a c k e d b y

h y d r o g e n wh en a t t a c h e d t o t h e a l p h a p o s i t i o n o f t h e h y d r o aro m atic rin g .

In the l a t t e r

r e s i s t a n t to dehydrogenatlon,

case,

t h e r i n g I t s e l f was

a n d o n l y a s m a l l amount

o f t h e m e t h y l 1 - n a p h t h y l k e t o n e was o b t a i n e d . T h e p r e s e n c e o f d o u b l e b o n d s i n t h e com pound t o b e d e h y d ro g e n a te d h a s g r e a t i n f l u e n c e upon t h e f i n a l r e s u l t s . I f d o u b l e b o n d s a r e l o c a t e d i n t h e s t a r t i n g m a t e r i a l so t h a t t h e compound a p p r o a c h e s an a r o m a t i c c o n d i t i o n , d e h y d r o g e n a t l o n w i l l t a k e p l a c e more r e a d i l y .

T h is can

be seen i n t h e c a s e o f t h e iso m e rs t e r p i n e n e and lim o n en e; th e form er i s su lfu r, the

c o n v e rte d to

cym ene i n a 5 0 $ y i e l d w i t h

w hile th e l a t t e r g iv e s

same c o n d i t i o n s

a y i e l d o f o n ly 15$ u n d e r

(1 1 ).

&UUF0R

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.

13

Svi.FUR

nc

The p ro b le m o f p u r i f i c a t i o n products is

q u ite im portant.

a re o b tained. products,

H,

of th e deh y d ro g en atlo n

In a ll

cases,

T he u s u a l p r o c e d u r e i s

com plex m ix tu r e s

to f r a c tio n a te th e

o r to ta k e advantage of p o l a r i t y d i f f e r e n c e s

se p a ra tin g the p ro d u cts.

in

F ractio n a l c r y s ta lliz a tio n

and th e fo rm atio n of d e r iv a tiv e s a re f r e q u e n tly r e s o r te d to . to

The m ethod o f c h r o m a to g r a p h y l e n d s i t s e l f

ad m irab ly

t h e problem o f p u r i f i c a t i o n o f t h e s e m i x t u r e s .

F requent­

l y n e u t r a l p r o d u c t s a r e o b t a i n e d a l o n g w i t h much t a r r y deco m p o sitio n p ro d u c ts .

The u s u a l m e th o d s o f i s o l a t i o n

a n d p u r i f i c a t i o n a r e e i t h e r l o n g a n d t e d i o u s o r t o no a v a il in th ese cases.

Chrom atography can be u s e d t o

s e p a r a t e t h e s e n e u t r a l p r o d u c t s from e a c h o t h e r and from contam inating im p u ritie s very e a s ily . I d e n t i f i c a t i o n o f d e h y d r o g e n a t l o n p r o d u c t s may b e m a d e b y c o m p a r i s o n w i t h known c o m p o u n d s o r t h e i r d e r i v a t i v e s a s t h e c a s e may b e .

I n t h e c a s e o f new c o m p o u n d s ,

u s e f u l means o f I d e n t i f y i n g u tilizatio n

of absorp tion

s tr u c tu r a l ty p es i s

sp ectra.

a

the

Com parison o f t h e

s p e c t r u m o f an u n i d e n t i f i e d compound w i t h t h a t o f a known r e f e r e n c e

com pound c a n o f t e n r e s o l v e a n y d o u b t s a s

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.

14

to

s tr u c tu r a l type.

The u s e f u l n e s s o f t h i s m e t h o d c a n b e

e x te n d e d by a s y s t e m a t i c s tu d y of t h e u l t r a v i o l e t tio n

s p e c t r a o f compounds p r e p a r e d by u n a m b ig u o u s m e th o d s .

A d i s c u s s i o n o f th e r e l a t i o n betw een s t r u c t u r e is

absorp­

in a l a t t e r

and s p e c t r a

sectio n of th is d is s e r ta tio n .

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.

15

D iscu ssio n of E xperim ental

T h e e x p e r i m e n t a l w o r k d e s c r i b e d h e r e was d i r e c t e d tow ard th e

sy n th esis of c e rta in

alicy cllc

compounds,

and

subsequent d eh y d ro g en atlo n a n d /o r is o m e riz a tio n to th e c o r r e s p o n d i n g a r o m a t i c compounds. i n t o two m ain s e c t i o n s : sis

T he w o r k was d i v i d e d

I-A n i n v e s t i g a t i o n o f th e

of n a p h th a le n e s w ith a lk y l o r a ry l

th e 1 -p o sltio n . 1-n ap h th o ls

II-A n in v e s tig a tio n

w ith a l i p h a t i c

su b stitu en ts

of the

acid s u b stitu e n ts

sy n th e­ in

sy n th e sis of i n t h e 2.-

p o sitio n . For convenience i n d is c u s s io n ,

th e fo reg o in g d iv is io n

w i l l be fo llo w e d . S ection I A s e r i e s o f 1 - s u b s t i t u t e d 3 , 4 - d l h y d r o n a p h t h a l e n e s were p r e p a r e d by t h e G-rlgnard r e a c t i o n b e tw e e n 1 - t - e t r a l o n e o r the a p p ro p ria te ly ria te

su b stitu te d 1-te tra lo n e

and th e ap prop­

alkyl or a ry l h a lid e .

2 - H, H H} 0 C t f 3 0 c H3 i 0 c H3 a lk y l or f ir y l The 3 , 4 - d l h y d r o n a p h t h a l e n e s w ere c o n v e r t e d t o t h e c o rre sp o n d in g n a p h th a le n e s w ith a p a l 1 adium -carbon c a t a l y s t .

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.

16

R PD-C

It

became a p p a r e n t a t t h e

s ta r t of the in v e stig a tio n

th a t a s e rie s of tetrahydronaphthalenes s tru c tu re to (1 2 ,1 3 )

certain n a tu ra lly

s im ila r In b a sic

o ccu rrin g p h e n o lic re s in s

c o u ld be o b t a i n e d from t h e 3 , 4 - d lh y d r o n a p h t h a l e n e s

by r e d u c t i o n . u ltrav io let

T h e se compounds w ere p r e p a r e d ,

and t h e i r

s p e c t r a were I n v e s t i g a t e d f o r com parison

w ith o th e r aro m atic system s.

+

H

PD-C

The f o l l o w i n g 1 - t e t r a l o n e s - w e re u s e d i n t h e G -rlgnard reactio n :

1 -te tra lo n e

(I),

6 , 7 -d im eth o x y -l-tetralo n e

7 -m eth o x y -l-tetralo n e ( I I ) , (III).

dffo

I

JL IH T h e o r g a n o m e t a l l i c c o m p o u n d s w e r e mad e f r o m b r o m o b e n z e n e , p -b ro m o an lso le,

4-brom overatrole,

and n - b u t y l b rom ide.

N - b u t y l b r o m i d e was I n c l u d e d t o p r o v i d e a s e r i e s o f r e f e r e n c e

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.

17

compounds f o r t h e s t u d y o f u l t r a v i o l e t

absorption sp e c tra .

T h e e f f e c t o f t h e n - b u t y l g r o u p on s o l u b i l i t y i s to

t h a t o f t h e p henyl group (1 4 ).

ance in the

com parable

T h is would be o f i m p o r t ­

study of p h y s io lo g ic a l a c t i v i t y .

T h e s y n t h e s i s o f 1 - t e t r a l o n e o f f e r e d no d i f f i c u l t i e s . ( 3 - B e n z o y l p r o p l o n i c a c i d ( I V ) w as made b y t h e m e t h o d d escrib ed in

’’O r g a n i c S y n t h e s i s "

k e t o a c i d (IV)

(15).

R ed u ctio n o f th e

to ^ - p h e n y l b u t y r l c a c i d (V ),w as c o n v e n ie n tly

e f f e c t e d w i t h t h e m ethod d e v e l o p e d by H o rn in g and R e i s n e r (16).

T he r e d u c t i o n was c a r r i e d o u t i n a c e t i c

acid at

60 -6 5 ° w ith a p a lla d iu m -c a rb o n c a t a l y s t .

CHx CHv CHv C0OH

Z5Z1 A q u a n t i t a t i v e y i e l d o f (V) was o b t a i n e d . t h e G lem m en se n r e d u c t i o n product in th is cleaner.

case,

(17)

A lthough

a f f o r d s a good y i e l d o f

t h e c a t a l y t i c m ethod i s

f a s t e r and

T h e c a t a l y t i c m e t h o d was a l s o u s e d i n t h e r e d u c ­

t i o n o f m ethoxy s u b s t i t u t e d ( 3 - b e n z o y lp r o p io n lc a c i d s (as d escrib ed l a t e r ) . 1-T etralone

(I)

was p r e p a r e d f r o m t h e a c i d c h l o r i d e

o f ^ - p h e n y l b u t y r i c a c i d (v) The a c i d c h l o r i d e ,

by an i n t r a m o l e c u l a r a c y l a t l o n .

i n b e n z e n e , was a d d e d t o a s o l u t i o n o f

aluminum b ro m id e i n b e n z e n e .

The m ethod i s

convenient

and a f f o r d s th e p ro d u c t i n good y i e l d .

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.

18

0

0

ii

Cl'6 .

A l8r3 Benzene

X Jo h n so n and G lenn (18) of th e F rie d e l-C ra fts ch lo rid e.

d escrib e another m o d ificatio n

i n v e r s e a d d i t i o n m ethod u s i n g aluminum

The a d v a n t a g e o f a l u m i n u m b r o m i d e i s

th at i t

is

s o l u b l e i n b e n z e n e a f f o r d i n g a h o m o g e n e o u s r e a c t i o n m e d iu m . A G r i g n a r d r e a c t i o n w as c a r r i e d o u t i n t h e u s u a l m anner w ith 1- t e t r a l o n e

(I)

and n - b u ty l brom ide.

HxcH,CHCH

YL D i f f i c u l t y was e n c o u n t e r e d i n t h e p u r i f i c a t i o n 3 , 4-dehydronaphthalene

(V I);

d istillatio n

t o p u r i f y t h e compound f o r a n a l y s i s . d eh y d ratio n of th e c a rb in o l, r e f l u x w ith a c e t i c s u lf u r ic acid .

of the

was n o t s u f f i c i e n t

To i n s u r e

com plete

t h e m a t e r i a l was h e a t e d u n d e r

a n h y d r i d e an d a few d r o p s o f c o n c .

The r e a c t i o n p r o d u c t was p u r i f i e d by

c h r o m a to g r a p h y on a lu m i n a .

T h i s m e t h o d o f p u r i f i c a t i o n was

used s u c c e s s fu lly throughout th e

e x p e r i m e n t a l work.

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.

The

19

p r o c e d u r e u s e d h e r e was o n e o f e l u t i o n

a n aly sis.

The c ru d e

co m p o u n d was a d s o r b e d o n a c o l u m n o f a l u m i n a f r o m a n o n ­ p o lar

so lv en t

(u s u a lly hexane,

a s m a l l amount o f b e n z e n e ) .

o r a m ix tu re o f h exane and

T h e c o l u m n w as d e v e l o p e d ,

and

t h e m a t e r i a l was e l u t e d w i t h a s e r i e s o f I n c r e a s i n g l y p o l a r so lv en t p a ir s

(m ix tu res of hexane and benzene,

in creasin g

th e p ro p o rtio n of benzene to in c re a s e th e p o l a r i t y

of the

so lv en t p a ir) D e h y d r o g e n a t l o n o f VI was e f f e c t e d b y h e a t i n g w i t h a p allad iu m -carb o n c a t a l y s t a t 300°.

PD-c 300°

An i m p o r t a n t f a c t o r i n of a lic y c llc

th e c a ta ly tic

compounds i s t h e c o n t i n u o u s a g i t a t i o n

e b u llu tio n of th e m ixture

(7).

stru ctu res,

It

or

F in e ly d iv id e d palladium

has th e p ro p e rty of s tro n g ly a t t r a c t in g hydrogen.

dehydrogenatlon

and a d s o rb in g

can add o r rem ove h y d ro g e n from c e r t a i n

w ith o r w ith o u t th e a id of m o le c u la r hydrogen.

T his p ro p e rty i s r e s p o n s ib le f o r i t s

use both as a hydro­

g e n a tio n c a t a l y s t and d e h y d ro g e n a tlo n c a t a l y s t .

It

is

n e c e s s a r y t o d i s l o d g e t h e a d s o rb e d h y d ro g en from t h e s u r f a c e of th e palladium to

e f f e c t dehydrogenatlon.

T his i s

u s u a l l y done by h e a t i n g u n d e r r e f l u x a m ix tu r e o f t h e

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.

20

compound t o b e d e h y d r o g e n a t e d a n d t h e c a t a l y s t In ert,

n eu tral

so lv en t

e b u llu tio n of the

(e x .:

i n an

trleth y lb en zen e).

The

s o lv e n t d i s l o d g e s t h e h y d ro g en from t h e

su rfa c e of th e palladium .

T h i s m e t h o d i s u s e f u l when t h e

a r o m a t i c p r o d u c t c a n be s e p a r a t e d from t h e d iffe re n c e s in p o la r ity ,

or v o la tility

s o lv e n t by

i n steam .

Dehydro­

g e n a tio n can a ls o be c a r r i e d o u t a t t h e b o i l i n g p o i n t of th e a lic y c llc compounds, cataly st resu lts

co m p o u n d ( 7 ) .

In th e case of high b o ilin g

s t i r r i n g o f a m i x t u r e o f t h e compound and

a t a h ig h tem perature w ill give th e d e s ir e d (6 ).

d ifficu lties

The l a s t

tw o p r o c e d u r e s a r e v a l u a b l e when

w ould be e n c o u n t e r e d i n

p r o d u c t from t h e

so lv en t.

se p a ra tio n of the

They w ere u s e d i n t h e

experim ental

work d e s c r i b e d h e r e s i n c e n e u t r a l p r o d u c t s w ere o b t a i n e d in

all

cases.

T h e r e d u c t i o n o f t h e 3 , 4 - d i h y d r o n a p h t h a l e n e VI was co n v en ien tly e f fe c te d in a c e tic

a c id a t 60-65° w ith

pallad iu m -carb o n c a ta ly s t.

1-P h e n y l-3 ,4 -d ih y d ro n a p h th a le n e

(V II)

was mad e i n

good y i e l d by t h e f o l l o w i n g m ethod:

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.

+

HCI

The p r o d u c t c o u l d n o t b e p u r i f i e d f o r a n a l y s i s by d istilla tio n .

Chrom atography gave a p u r e p r o d u c t ,

as

i n d ic a te d by a n a ly s is . D ehydrogenation of 3 ,4 -d ih y d ro n a p h th a le n e was c a r r i e d . o u t by h e a t i n g i t

(V II)

w ith p allad iu m -ca rb o n

c a t a l y s t at 500°.

Pp-C 300 ‘

+ H-

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.

22

A method u s i n g is

d escrib ed in

s u l f u r f o r d e h y d r o g e n a tio n o f VII

"O rganic S y n th e s is "

(19).

The r e d u c t i o n o f V II was c a r r i e d o u t i n a c e t i c a c id a t 60-55° w ith p a lla d iu m -c a rb o n

c a taly st.

+ H, The G -rignard r e a c t i o n b e tw e e n 1 - t e t r a l o n e

(I)

and

p-brom oam isole p ro c e e d e d r e a d i l y once th e o r g a n o m e ta llic co m pound was f o r m e d . OcH3

hr

u

OCH,

-H *o The f o r m a t i o n o f an o r g a n o m e t a l l i c

co m p o u n d f r o m

p-b ro m o an iso le p ro ceed ed w ith d i f f i c u l t y . to I n i t i a t e

It

was n e c e s s a r y

t h e r e a c t i o n wiTJh t h e u s e o f e l e m e n t a r y i o d i n e

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.

23

and a few d ro p s o f m e th y l i o d i d e . tu r e f o r a sh o rt tim e,

A f t e r h e a t i n g t h e mix­

t h e f o r m a t i o n o f t h e G-rignard

re a g e n t proceeded sp o n tan eo u sly .

The r e a c t i o n h a s b een

d escrib ed prev io u sly (4). T h e d e h y d r o g e n a t i o n o f V I I I was c a r r i e d o u t u s i n g an i n e r t

so lv en t

(phenyl eth er)

a s t h e r e a c t i o n m e d iu m .

T h e d e h y d r o g e n a t i o n w as a c c o m p l i s h e d c a t a l y t i c a l l y w i t h p a l 1adlum -carbon.

PD- c

+ H.

PHENYL ETH ER

A c r y s t a l l i n e p r o d u c t was o b t a i n e d . of th e poor re s u lts

As a c o n s e q u e n c e

o b t a i n e d u s i n g a s o l v e n t medium i n

t h i s d eh ydrogenation,

t h e m ethod o f h e a t i n g an i n t i m a t e

m i x t u r e o f com pound a n d c a t a l y s t w as f o l l o w e d i n o t h e r cases.

T he d i f f i c u l t i e s

of the p roduct. tra ces

of so lv en t,

success. but i t

It

e n c o u n t e r e d were i n t h e p u r i f i c a t i o n

w as v e r y d i f f i c u l t

a n d c h r o m a t o g r a p h y was u s e d w i t h o u t

Steam d i s t i l l a t i o n

was n e c e s s a r y t o

w ith p entane,

t o rem ove t h e l a s t

rem oved most o f t h e

tritu ra te

and t h e l a s t

so lv en t,

th e product re p e a te d ly

tr a c e s of so lv en t

c o u ld n o t be

rem oved.

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.

24

The d e h y d r o g e n a tio n o f V I II h a s b e e n d e s c r i b e d

(4 ,3 5 ).

S u l f u r o r s e l e n i u m was u s e d . T h e r e d u c t i o n o f V I I I was c a r r i e d o u t I n t h e u s u a l way w i t h a p a l l a d i u m - c a r b o n c a t a l y s t i n a c e t i c 60-65°.

acid at

Q H

+ H, The p r e p a r a t i o n o f t h i s

co m p o u n d h a s b e e n r e c e n t l y

d e s c r i b e d by M entzer and cow orkers ( 2 0 ) . To c o m p l e t e t h i s

series,

it

w ould b e d e s i r a b l e t o

c a rry out th e fo llo w in g r e a c tio n s .

4-

JL

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.

An e x a m i n a t i o n o f t h e l i t e r a t u r e w i t h r e g a r d t o t h e s e r e a c t i o n s w as n o t e n c o u r a g i n g .

T he s y n t h e s i s o f t h e

n e c e s s a r y a r y l h a l i d e s a p p a r e n t l y was a l o n g and t e d i o u s process.

G-asparl (2 1 ) d e s c r i b e d a m eth o d w hich i n v o l v e d

a n e l a b o r a t e a p p a r a t u s a n d a l o n g p e r i o d t o mak e 4 - b r o m o v eratro le. A c o n v e n ie n t m ethod of b r o m i n a t i o n o f v e r a t r o l e to o b ta in 4-brom overatrole in ed.

e x c e l l e n t y i e l d w as d e v e l o p ­

The u s e o f p y r i d i n i u m b ro m id e p e r b r o m i d e a s a b ro m -

i n a t i n g agent has been d e s c rib e d r e c e n tly

(2 2 ,2 3 );

r e a g e n t w as u s e d h e r e w i t h a c e t i c a n h y d r i d e a s t h e

th is so lv en t.

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.

26

0 CHj

Act tic Br-Bn. The m ethod c o n s i s t s

8r

in adding th e h ro m in atln g agent

to a s o lu tio n of v e r a tr o le tem p eratu re.

in a c e tic

A c r y s ta l of f e r r i c

a n h y d r i d e a t room

ch lo rid e is

t h e m i x t u r e warmed a t 45° f o r f i v e m i n u t e s . has

6’

h'tdriJt v Fe+*

added,

and

P a r k e r (24)

em ployed t h i s m ethod i n h r o m i n a t i n g p y r o g a l l o l

trim e th y l eth er.

oc

Ha Acetic

Ct^O

W -J

F e« -

Bk

N - H B v Bv.

T h e s y n t h e s i s o f XI I n v o l v e s a s e v e r a l s t e p

och3 cy

^

y

sy n th esis.

o c «3 c» i

otw 3

OLO

s< w i> ) c V

^

COON

j tc*

ocHi nh,

C07IH%,

C0C/ J£H3

ocHj K l

>

* NxCI

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.

x

27

The s y n t h e s i s o f l , 2 , 3 - t r i m e t h o x y - 5 - i o d o b e n z ; e n e was not attem pted because p rev io u s I n v e s tig a to rs th at i t

d i d n o t form a G r ig n a r d r e a g e n t .

form a l i t h i o

d e r i v a t i v e was m a d e ( 2 5 ) ,

(2 5 ,2 6 )

found

An a t t e m p t t o b u t t h e m ethod

was n o t s u c c e s s f u l . G rig n a rd (27) m etallic

s t u d i e d t h e f o r m a t i o n o f an o r g a n o -

co m p o u n d f r o m 4 - b r o r a o v e r a t r o l e .

4 - b r o m o v e r a t r o l e r e a c t s w i t h m agnesium , in itia lly

form ed c o a t s th e

p revents fu rth e r re a c tio n .

He f o u n d t h a t b u t t h a t t h e com plex

s u r f a c e o f t h e m agnesium a n d He f o u n d t h a t

if

a larg e

e x c e s s o f a s i m p l e a l k y l h a l i d e was a d d e d w i t h 4 - b r o r a o ­ v eratro le,

t h e fo rm a tio n o f a sim ple o r g a n o m e ta lllc

compound w ould c o n t i n u o u s l y c l e a n t h e s u r f a c e o f t h e m agnesium a n d a l l o w t h e 4 - b r o m o v e r a t r o l e t o r e a c t .

T his

e n t r a i n m e n t m e t h o d v/as t r i e d u s i n g m e t h y l i o d i d e a s t h e e n tra in in g agent.

The r e a c t i o n m anner.

s e q u e n c e w as c o n t i n u e d i n t h e u s u a l

The p r o d u c t o f t h e r e a c t i o n was d i s t i l l e d u n d e r

reduced p re ssu re ,

and v a r i o u s f r a c t i o n s were I s o l a t e d

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.

28

co n sistin g of 1 -te tra lo n e ,

v eratro le,

4-brom overatrole,

and l-ra e th y l-5 ,4 -d ih y d ro n a p h th a le n e .

A s m a ll amount o f

t a r r y r e s id u e rem ained in th e d i s t i l l i n g

fla sk .

w as h e a t e d w i t h p a l l a d i u m - c a r b o n c a t a l y s t . c h r o m a t o g r a p h e d on a l u m i n a , c ry stallin e

T h e r e s i d u e was

and a v e r y s m a ll amount o f

s u b s t a n c e w as o b t a i n e d .

a s X by a n a l y s i s .

T his

T h i s was i d e n t i f i e d

F u rth e r a p p lic a tio n to o th e r 1 - te tr a lo n -

c s was n o t a t t e m p t e d . The p o s s i b i l i t y

of form ing a l i t h i o

4 - b r o m o v e r a t r o l e was n o t i n v e s t i g a t e d . ers

(28)

d eriv a tiv e of G-ilman a n d c o w o r k ­

s tu d i e d th e r e a c t i o n betw een m e t a l l i c l i t h i u m

and p -b ro m o an lso le .

They fo u n d t h a t t h e f o l l o w i n g t o o k p l a c e .

W i t t i g and cow orkers (29) r e a c t i o n and s t a t e d t h a t i f a re both p r e s e n t,

stu d ied th e

same m e t a l a t i o n

r e a c t i v e h y d rogens and h a lo g e n s

the usual p re d ic tio n s

concerning th e

p r o d u c t s c a n n o t b e made. The n e x t

s e r i e s o f compounds i n v o l v e d t h e u s e o f

7 -m e th o x y -l-tetralo n e H ersh b erg (30)

f o r th e

(II).

The m eth o d o f F i e s e r and

su c cin o y la tio n of p h enolic e th e rs

was u s e d t o make ( 3 - ( 4 - m e t h o x y b e n z o y l ) - p r o p i o n i c a c i d .

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.

29

S u c c i n i c a n h y d r i d e was c o n d e n s e d w i t h a n i s o l e p r e s e n c e o f aluminum c h l o r i d e , c h l o r e t h a n e and n i t r o b e n z e n e

in th e

w ith a m ixture of t e t r a -

(4 :1 )

as th e

so lv en t.

^ - ( 4 - m e t h o x y p h e n y l ) - b u t y r i c a c i d was o b t a i n e d by th e c a t a l y t i c

re d u c tio n of (J-(4-m ethoxybenzoyl)-

p ro p lo n ic a c id w ith palladium -carbon p r e p a ra tio n of t h i s

c ataly st.

Th e

compound h a s b e e n d e s c r i b e d by

H o rning and R e is n e r (1 6 ).

T h i s m e t h o d when u s e d w i t h

m e th o x y s u b s t i t u t e d a r y l k e t o compounds g i v e s b e t t e r r e s u l t s t h a n t h e C le m m e n s e n m e t h o d ,

sin ce dem ethylatlon

d o e s n o t accompany r e d u c t i o n . Several v a ria tio n s

of a F rie d e l-C ra fts

a c y l a t i o n t o make 7 - m e t h o x y - l - t e t r a l o n e rep orted

(3 1 ,3 2 ,5 3 ).

(II)

The g e n e r a l m ethod i s

in tram o lecu lar h av e been t o form t h e

__ a c i d c h l o r i d e o f ^ - ( 4 - m e t h o x y p h e n y l ) - b u t y r i c a c i d a n d c y c liz e in th e presence of a s u ita b le and N athan (31) ch lo rid e

Thomas

a n d Bac hmann a n d H o r t o n ( 3 2 ) u s e d s t a n n i c

(benzene as so lv e n t)

and S h e l d r i c k (33)

w ith good r e s u l t s .

u s e d aluminum c h l o r i d e

eth an e as s o lv e n t) . satisfa cto ry

c a taly st.

(tetra ch lo ro -

T h i s m e t h o d 7/a s f o u n d t o b e m o r e

s i n c e a p u r e r p r o d u c t was o b t a i n e d .

and H ersh b erg (34) p r e p a r e d I I flu o rid e d ire c tly

H aw orth

on t h e a c i d .

F ieser

u s in g anhydrous hydrogen T he y i e l d w as n o t a s g o o d

as t h o s e o b t a i n e d w ith t h e o t h e r m ethods ( 6 1 ^ ). A s e r i e s o f G-rlgnard r e a c t i o n s w ere c a r r i e d o u t w i t h

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.

30

7 -m e th o x y -l~ tetralo n e. the

It

was f o u n d a d v i s a b l e t o r e p l a c e

e t h e r i n w h i c h t h e o r g a n o m e t a l l i c c o m p o u n d was f o r m e d

w ith benzene,

and add th e k e to n e In benzene s o l u t i o n .

k e t o n e was m o r e s o l u b l e i n b e n z e n e t h a n I n e t h e r .

Th e

The

s o l u b i l i t y f a c t o r w a s o f p r i m e I m p o r t a n c e w h en 6 , 7 - d i m eth o x y -l-tetra lo n e

(III)

w as u s e d I n t h e G r i g n a r d r e a c t i o n

as w i l l be seen in a l a t e r

sectio n .

A d e fin ite

in d icatio n

o f a r e a c t i o n was o b t a i n e d when b e n z e n e was u s e d , t e m p e r a t u r e r i s e was n o t e d ,

w ith a c e tic acid .

and n - b u ty l brom ide,

went sm o o th ly .

a

carried

D e h y d r a t i o n was c a r r i e d o u t

a n h y d rid e and a few d ro p s o f conc.

I t w as n e c e s s a r y t o

e.

due to th e exotherm ic r e a c t i o n .

The r e a c t i o n b e tw e e n I I out in benzene,

1.

su lfu ric

chrom atograph t h e p ro d u c t t o

ob tain m a te ria l of a n a ly tic a l p u rity .

+ CH,CHl.CH1 CHvHTj9r

C«1CH,CHvCH3

00'

o

CHjCHj .CHj .CWj

a r

D e h y d r o g e n a t i o n o f X I I was c a r r i e d o u t b y h e a t i n g a m i x t u r e o f t h e co m p o u n d a n d p a l l a d i u m - c a r b o n c a t a l y s t a t 500°.

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.

31

VKvCHxCHj

R e d u c t i o n o f X I I was e f f e c t e d v / I t h p a l l a d i u m - c a r b o n cataly st

In a c e tic

a c id a t 60-65°.

ay,

I t may b e n o t e d a t t h i s p o i n t t h a t products,

d ih y d ro n ap h th alen es,

a ll reactio n

tetrah y d ro n ap h th alen es,

and n a p h th a le n e s were p u r i f i e d by c h ro m a to g ra p h y a s a m a tte r of n e c e s s ity in procedure in o th e rs. e a r l i e r in t h i s

some c a s e s a n d a s a r o u t i n e T he s u c c e s s f u l r e s u l t s m e n t i o n e d

d isc u s s io n w arrented th e a p p lic a tio n

chrom atography to

all

compounds.

of

S e v e r a l exam ples w i l l

b e shown w h e r e s e e m i n g l y i n t r a c t a b l e

t a r s were p u r i f i e d

by t h i s m ethod (an exam ple h a s been m e n tio n e d i n t h e iso latio n

of X ).

The G r i g n a r d r e a c t i o n b e tw e e n 7 - m e t h o x y - l - t e t r a l o n e a n d b ro m o b e n z e n e was c a r r i e d o u t i n b e n z e n e .

D ehydration

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.

32

w ith a c e tic su ccessfu l.

a n h y d rid e and conc.

s u l f u r i c a c i d was n o t

A n aly sis of th e pro d u ct In d ic a te d t h a t

was t h e c a r h i n o l .

it

T h is e f f e c t m ight b e a t t r i b u t e d to t h e

i n d u c t i v e e f f e c t o f th e m ethoxyl group in th e 7 - p o s l t l o n , r e s u l t i n g i n t h e h y d r o x y l g r o u p b e i n g h e l d more t i g h t l y . It

was n e c e s s a r y t o r e s o r t t o

agent;

a m o re p o w e r f u l d e h y d r a t i n g

p h o s p h o r o u s o x y c h l o r i d e was c h o s e n .

was c a r r i e d o u t i n a b e n z e n e s o l u t i o n . h as been r e p o r te d as a s o li d

(35),

Th e d e h y d r a t i o n

The p r o d u c t X I I I

but the m a te ria l

o b t a i n e d h e r e was a l i q u i d .

Be»zrwe

D e h y d r o g e n a t i o n o f X I I I w as e f f e c t e d b y h e a t i n g a m i x t u r e o f t h e co m p o u n d a n d p a l l a d i u m - c a r b o n c a t a l y s t a t 300°.

How ell and R o b e r ts o n

(35)

c a rrie d out the

d e h y d ro g e n a tio n of X III w ith selen iu m . jso lid ,

They o b t a i n e d a

b u t t h e m a t e r i a l o b t a i n e d h e r e was a l i q u i d .

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.

The r e d u c t i o n o f X I I I was c a r r i e d o u t i n t h e u s u a l manner w ith p a lla d iu m -c a rb o n c a t a l y s t

in a c e tic

acid at

60-65°.

It

was d e c i d e d t o u s e p h o s p h o r o u s o x y c h l o r i d e a s

t h e d e h y d r a t i n g a g e n t i n most o f t h e t a l work a f t e r p o o r r e s u l t s an h y d rid e and conc.

su b se q u e n t experim en­

were o b ta in e d w ith a c e t i c

s u lf u r ic acid .

The G -rignard r e a c t i o n b e tw e e n I I was c a r r i e d o u t i n b e n z e n e .

and p-brom oanisole

D - e h y d r a t l o n w as e f f e c t e d

w ith phosphorous o x y c h lo rid e .

0CH3

B eiarne.

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.

34

0CH3

0 CH3

m

A dark,

viscous

s u b s t a n c e was o b t a i n e d a s t h e

product of th e re a c tio n . co lo rle ss,

cry stallin e

C hrom atography y i e l d e d a

so lid ,

m. p .

60-61°.

h a s b een r e p o r t e d by B addar and El A s s a l (56) m. p .

77-78°.

The a n a l y s i s

The compound as a so lid ,

and th e u l t r a v i o l e t

absorption

s p e c t r u m o f t h e l o w e r m e l t i n g compoun d i n d i c a t e d t h a t w as XIV. th is

It

T h e r e may b e a p o s s i b i l i t y o f p o l y m o r p h i s m i n

case. T h e d e h y d r o g e n a t i o n o f XIV was c a r r i e d o u t i n t h e

' u s u a l m anner by h e a t i n g a m i x t u r e o f t h e compound w i t h pallad iu m -carb o n c a ta ly s t (36)

a t 300°.

B a d d a r a n d E l As s a l

r e p o r t e d a d e h y d r o g e n a t i o n o f XIV w i t h s e l e n i u m .

T h e m. p .

o f t h e tw o p r o d u c t s w e r e i n a g r e e m e n t . £ch3

CH30 pP-c>,

+

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.

H i.

35

The r e d u c t i o n

o f XIV w a s c a r r i e d o u t i n t h e u s u a l

way w i t h p a l l a d i u m - c a r b o n c a t a l y s t i n a c e t i c a c i d a t 60-65°.

OCHj

T h e n e x t s e r i e s o f r e a c t i o n s w as c a r r i e d o u t w i t h 6 , 7 -d im eth o x y -l-tetralo n e It

(III)

a s one o f th e r e a c t a n t s .

was p r e p a r e d b y t h e f o l l o w i n g m e t h o d .

(3 -(3 ,4 -D lm eth -

o x y b e n z o y l ) - p r o p i o n i c a c i d was p r e p a r e d b y t h e

succlnoy-

latio n

o f v e r a t r o l e as d e s c r i b e d by F i e s e r and H e r s h b e r g

(30).

T h e k e t o a c i d was r e d u c e d q u a n t i t a t i v e l y t o

i f - ( 3 , 4 - d im e t h o x y p h e n y l ) - b u ty r i c a c i d by t h e m ethod o f H orning and R e is n e r (1 6 ).

The a d v a n t a g e o f t h i s m eth o d

o v e r t h e C le m m e n s e n r e d u c t i o n i s

apparent here;

dem ethy-

l a t i o n d id not occur. T h e c y c l i z a t l o n o f CHjO

D e h y d r o g e n a t i o n w as c a r r i e d o u t i n t h e u s u a l w a y . A m i x t u r e o f XV a n d p a l l a d i u m - c a r b o n c a t a l y s t w a s h e a t e d a t 300°. oixCHtCHjCHa

PD-C , * CHjO

T h e r e d u c t i o n o f XV w as c a r r i e d o u t i n a c e t i c a t 60-65° w ith p a lla d iu m -c a rb o n c a t a l y s t .

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.

+ H-*-

acid

38

The r e a c t i o n b e tw e e n I I I

and brom obenzene h as been

r e p o r t e d by H ow ell and R o b e r t s o n ( 3 5 ) .

The r e a c t i o n was

c a r r ie d out h ere in benzene.

A c r y s t a l l i n e p r o d u c t was

o b ta in e d p r io r to d ehydration

( p r o b a b l y XVI),

m a t e r i a l w as h e a t e d w i t h a c e t i c o f conc.

su lfu ric

but th e

a n h y d r i d e and a few d r o p s

a c id to I n s u r e com plete d e h y d ra tio n .

Bew ztrw

HCI >

(HjO

D ehydrogenation of th e 3 , 4 -d ih y d ro n a p h th a le n e was c a r r i e d o u t i n

t h e u s u a l way.

A m i x t u r e o f XVI a n d

p a l l a d i u m - c a r b o n c a t a l y s t was h e a t e d a t 3 0 0 ° . and R o b e r ts o n (35)

(XVI)

H ow ell

re p o rte d th e dehydrogenation u sin g

selenium .

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.

T h e r e d u c t i o n o f XVI was c a r r i e d o u t i n a c e t i c

acid

a t 60-65° w ith p a lla d iu m -c a rb o n c a t a l y s t .

+ HlL The r e a c t i o n b e tw e e n t h e k e t o n e I I I was c a r r i e d o u t i n b e n z e n e .

and p -b ro m o a n lso le

D e h y d r a t i o n w as e f f e c t e d w i t h

phosphorous o x y c h lo rid e .

A dark,

o b ta in e d as th e p ro d u c t.

C hrom atography o f t h i s m a t e r i a l

y ie ld e d a m ajor f r a c t i o n

v i s c o u s m a t e r i a l was

c o n sistin g of a g lassy

substance

(X V II).

0CH3

0 n *|B r

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.

231 D e h y d r o g e n a t i o n was c a r r i e d o u t b y h e a t i n g a m i x t u r e o f XVII a n d p a l l a d i u m - c a r b o n c a t a l y s t a t 3 0 0 ° . s u b s t a n c e w as a l s o

obtain ed in th is

A glassy

case.

QcH3

0CW3

P tX

+ H>.

3000

R e d u c t i o n o f XVII was c a r r i e d o u t i n a c e t i c a c i d a t 60-65° w ith p a llad iu m -ca rb o n c a t a l y s t .

A cry stallin e

s u b s t a n c e was o b t a i n e d .

+ Hv

PD-C

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.

41

The f o l l o w i n g t a b l e

sum m arizes t h e p h y s i c a l form s

o f t h e compounds o b t a i n e d . Parent dlh y d ro n ap h th alen e

tetrah y d ro n ao h th alen e

naphthalene

VI

liq u id

liq u id

liq u id

VII

liq u id

liq u id

liq u id

V III

so lid ,

m .p.

7 3 .5 -7 4 .5 °so lid ,

m. p .

66-67°

so lid , m .p. 1 131 14.5° X s o l i d , m.p 118-119°

X II

liq u id

liq u id

liq u id

X III v iscous o i l

liq u id

viscous o i l

XIV

so lid ,

XV

liq u id

XVI

so lid ,

XVII g l a s s

m .p.

m .p.

60-61°

85-86°

so lid ,

m .p.

90-91°

s o l i d , m .p. 84-856

liq u id

s o l i d , m .p. 48-50°

v iscous o i l

s o l i d , m .p. 103-104°

so lid ,

m .p.

61-62°

glass

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.

42

S ection II

T his s e c tio n d e s c rib e s to th e

certain

experim ents d i r e c t e d

s y n th e sis of 1 -n ap h th o ls w ith a l i p h a t i c

stitu e n ts

in the 2 -p o sltlo n ,

a c id sub­

by means o f d e h y d r o g e n a t i o n

procedures.

OH (cHjyCOOH

I t was d e c i d e d t o

explore th e p o s s i b i l i t y

aro m atizin g th e corresponding 1 - te tr a lo n e

of

a c id to o b ta in

th e naphthol.

T h e s i m p l e s t member o f t h e 1 - t e t r a l o n e l-tetralo n e-2 -acetlc

s e r i e s was

a c id (X V III). 0

B erg s (40)

a n d Bac hmann a n d J o h n s o n ( 4 1 )

rep o rted

th e fo llo w in g s y n th e sis of X V III:

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.

43

c Z o ztM

(Q cooctfe)

NaOEt

rO£t(rtt)

(V aO M c) >

COOZt(Mt)

N & O E tfo ) . BvCHiCOOft ( n t ;

coO E -t(M e)

WvC00 E t i h w

CHX C O O H

HjdlrOlxSISj

esteyj and £od/v.>n 6thoxide

Bev^S-

and

J o lw iO T j-

He th y I e ste rs

and

Sod/nin

Tnet hoxide.

B ergs (40)

a ls o r e p o r t s the

f o ll o w i n g m ethod.

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.

44

N&OEt

< ^ ~ ^ C H v C H y Bi- + CHx (COO£t)^

t)S*pon

V

//

cHxCHiCH (cooet)v

2) B r o w a-cO v

f) p elsA lC h

•OkCHxCh/BrCOCI

\

i

CHi(coOEt)+

cH%(iOO£iY COOH

H ydrol. ^ v C

B ac hmann a n d J o h n s o n ( 4 1 )

r e p o r t t h e above m ethod

w i t h t h e f o l l o w i n g m o d i f i c a t i o n t o o b t a i n XIX.

is B ergs

(40)

attem p ted to o b ta in th e te tr a lo n e

(XVIII)

by t h e f o l l o w i n g m ethod.

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.

" W a fo o e t),

V

Q

« « &

COOft

CHxCOOH

»

clit -z e The c y c l i z a t l o n d i d n o t work w ith any o f t h e a g e n t s used in c lu d in g conc.

su lfu ric

acid.

I t was d e c i d e d t o r e i n v e s t i g a t e t h e a b o v e m e t h o d sin ce I t

o ffe re d th e

sh o rtest

and most c o n v e n ie n t r o u t e

to X V III. E arlier re su lts

o f A tw o o d ,

Stevenson,

and T horpe ( 4 2 ),

a n d more r e c e n t l y t h o s e o f H o r n in g and F i n e l l i d ic a te d th a t th e use of s u lf u ric

(43),

acid under s u ita b le

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.

in ­

c o n d i t i o n s w ould c y c l i z e compounds d e r i v e d from i f - p h e n y l b u ty rlc acid .

The s u b s t i t u t e d

}f-p h en y lb u ty ric a c id

(XX)

w as p r e p a r e d a c c o r d i n g t o B e r g s a n d c y c l l z e d s u c c e s s f u l l y w ith s u lf u r ic ac id .

n

0

XX The d e h y d r o g e n a t i o n a n d i s o m e r i z a t i o n o f h y d r o a r o m a tlc k e to n e s to p h e n o ls have been r e p o r t e d by numerous au th o rs

(7 ,4 4 ,4 5 ).

The work o f L l n s t e a d an d M i c h a e l i s

( 7 ) was r e p e a t e d w i t h 1 - t e t r a l o n e u s i n g t r i m e t h y l b e n z e n e , trleth y lb en zen e,

and p h e n y l e t h e r as t h e s o l v e n t s r a t h e r

th a n p-cym ene.

0

The r e s u l t s

o b t a i n e d were i n ag reem en t w ith t h o s e o f

L in s te a d and M ic h a e lis

(See T ab le I ,

o f 4 0 -5 0 $ were o b t a i n e d . L i n s t e a d and M ic h a e l is ; genation led also

ex p erim en tal).

Y ields

An i m p o r t a n t e f f e c t w as n o t e d b y th e high tem p eratu re of dehydro­

to h y d ro g e n o ly sls

and c o n se q u e n t f o r m a tio n

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.

47

of n ap h th a le n e as a b y -p ro d u c t. Newman a n d Mangham ( 1 0 )

stu d ie d the c a ta ly tic

de­

h y d r o g e n a t i o n o f t h e f o l l o w i n g t y p e s o f compounds.

x-oxygenated sid e chain such as: -

cooch 5

-COCH^, -CHgOH,

, -CHO.

T h e y f o u n d t h a t t h e r e w as a l o s s o f o x y g e n t h r o u g h re d u c tio n of k e to n ic carbonyl groups,

o r de.carbonylatlon of

aldehydes. In th i3

work,

a series

o f d e h y d r o g e n a t i o n s was c a r r i e d

out w ith l - t e t r a l o n e - 2 - a c e t i c

a c id and i t s

a palladium -carbon c a ta ly s t.

Th e r e s u l t s

T able I I ,

la c to n e u sin g a re given in

experim ental.

CHxCOOH

CHiCOOH

p D- C Tyt7r»eth«l

.

[U S /

AM 0 f

P D -C T rie tU I

h e n y l v a l e r l c a c i d . — A m i x t u r e o f 66 g . ( 0 . 1 9 mole) 100 m l.

of

e t h y l |3 ,|3 - d i c a r b e t h o x y - S - p h e n y l v a l e r a t e ,

of a c e tic acid ,

a n d 5 00 m l .

of conc.

a c i d was h e a t e d u n d e r r e f l u x f o r t e n h o u r s . m i x t u r e was e x t r a c t e d w i t h t h r e e 1 5 0 - m l . ethyl a c e ta te

(1 :1 ).

_v:ater and d r i e d removed;

The c o o le d

p o rtio n s of eth er-

The e x t r a c t s w ere w ashed w e l l w ith

(m agnesium s u l f a t e ) .

The s o l v e n t s were

t h e r e s i d u e was a n a l m o s t q u a n t i t a t i v e

f^-carboxy- S - p h e n y l v a l e r i c aqueous a c e t i c

acid.

y ie ld of

R ec ry stalliza tio n

a c id pro v id ed c o lo r le s s m a te r ia l,

1 3 6 - 1 3 7 .5 ° ^ r e p o r t e d m .p. 1 -T etralo n e-E -ac etlc m ole)

h ydrochloric

136°

m .p.

(40)3.

a c id . — A so lu tio n of 3 g.

o f ^ - c a r b o x y - & - p h e n y l v a l e r i c a c i d i n 25 m l .

s u l f u r i c a c i d v/as m a i n t a i n e d a t and th e n a llo w e d t o

(0 .013

of conc.

55-60° f o r t h i r t y m in u tes,

s t a n d o v e r n i g h t a t room t e m p e r a t u r e .

The s o l u t i o n was p o u r e d on i c e , cry stallizatio n

from

and a llo w e d to

o f t h e p r o d u c t w as c o m p l e t e d .

p r o d u c t v/as s e p a r a t e d ,

washed w ith w a te r ,

stan d u n t i l The c r u d e

and d r i e d in

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.

105

vacuo to y ie ld 1 .5 g. 105°.

(57$)

of m a te ria l m elting at 104-

R e c r y s t a l l i z a t i o n from e t h y l a c e t a t e - p e n t a n e gave

a co lo rle ss

sam ple,

m .p.

1 0 8 -1 0 9 ° ^ r e p o r t e d m .p.

109-110°

(40)] . 2 - B r o m o - l - t e t r a l o n e - 2 - a c e t i c a c i d . — One g r a m ( 0 . 0 0 5 m ole)

of 1 - t e tra lo n e -2 -a c e tic

of chloroform .

a c i d w a s d i s s o l v e d i n 10 m l .

Ten m i l l i l i t e r s

of a chloroform

so lu tio n

c o n t a i n i n g a n e q u i v a l e n t a m o u n t o f b r o m i n e w as a d d e d i n sm all in crem en ts to th e k etone b r o w n c o l o r was d i s c h a r g e d ,

s o lu tio n w ith shak in g .

and w h ite fumes w ere e v o lv e d .

A f t e r s t a n d i n g a t ro om t e m p e r a t u r e f o r t h r e e h o u r s , s o l v e n t v/as r e m o v e d b y e v a p o r a t i o n t o

y i e l d 1 .2 g.

o f a l i g h t brown s y r u p w h ic h soon c r y s t a l l i z e d 129-139°). coal.

the (84$)

(m .p.

An e t h e r s o l u t i o n v/as d e c o l o r i z e d w i t h c h a r ­

T h e r e s i d u e was r e c r y s t a l l i z e d t h r e e t i m e s f r o m

benzene. m .p.

The

A co lo rle ss,

cry stallin e

s o l i d was o b t a i n e d ,

137-138°. A n a l . C a l c ' d f o r G^gH-j^Br 0 ^ : Found:

C,

T e tra lln -2 -a c e tlc R e i s n e r (16) ( 0 . 0 1 mole) 10 m l .

w as u s e d .

h a lf hours.

50.90;

H,

3 .9 2 .

H, 4 . 1 1 .

a c i d . — The m e t h o d o f H o r n i n g a n d The c a t a l y t i c

of l- te t r a l o n e - 2 - a c e t i c

of a c e tic

cataly st.

50.70;

C,

r e d u c tio n of 2 g.

a c i d was e f f e c t e d i n

a c i d a t 6 0 - 6 5 ° w i t h 5$ p a l l a d i u m - c a r b o n

T h e r e d u c t i o n v/as c o m p l e t e d i n t h r e e a n d o n e T h e c a t a l y s t w as r e m o v e d b y f i l t r a t i o n

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.

and

106

washed w ith e t h y l a c e t a t e . d istillatio n . m .p.

A c r y s ta llin e resid u e

85-87°.

charcoal.

T h e s o l v e n t s w e r e r e m o v e d by (1 .8 g .)

rem ained,

An e t h e r s o l u t i o n was d e c o l o r i z e d w i t h

Two r e c r y s t a l l i z a t i o n s

yield ed c o lo rle ss

cry stals

(m .p.

A nal. C a lc 'd f o r Found:

from e t h e r - p e n t a n e 87-88°). C, 7 5 . 7 6 ; H, 7 . 4 2 .

C, 7 5 . 5 2 ;

H,

7.60.

L actone o f 1 - t e t r a l o n e - 2 - a c e t i c a c i d . — A m ix tu re of 1 .2 5 g. m l.

( 0 .0 0 6 m ole)

of l-te tra lo n e -2 -a c e tic

a c i d a n d 25

o f a c e t i c a n h y d r i d e v/as h e a t e d u n d e r r e f l u x

hours.

T h e m i x t u r e w as c o o l e d a n d p o u r e d i n t o

o f cold w ater. two h o u r s .

T h e m i x t u r e was a l l o w e d t o

A red o il

(1 .0

The m a t e r i a l w a s d r i e d i n v a c u o , m .p.

200 m l .

stan d fo r

s e p a r a te d and c r y s t a l l i z e d .

v/as c o l l e c t e d b y f i l t r a t i o n

v/as r e c o v e r e d ,

f o r two

The

g. ) and washed w ith w a te r . and 1 g. o f a r e d s o l i d

80-97°.

T h e s o l i d w as t r i t u r a t e d w i t h c o l d e t h e r u n t i l m o s t of th e

c o l o r was r e m o v e d .

rem ained, ch arco al. Ice)

A yellow ,

w h i c h w as d i s s o l v e d i n

c r y s ta llin e resid u e

e th e r and d e c o lo r iz e d w ith

Two r e c r y s t a l l i z a t i o n s f r o m e t h e r - p e n t a n e

gave a l i g h t

yellow s o lid ,

m .p. 1 0 1 - 1 0 2 ° .

(Dry

The

m a t e r i a l was n o t c h a r a c t e r i s e d f u r t h e r . A series

o f d e h y d r o g c n a tio n s were c a r r i e d o u t u n d e r

v a r y i n g c o n d i t i o n s on l - t e t r a l o n e - 2 - a c e t i c a c i d and i t s la c to n e w ith a p allad iu m -carb o n c a t a l y s t .

I n w o r k i n g up

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.

107

th e products, p resent,

it

w as a p p a r e n t t h a t t h r e e f r a c t i o n s w e r e

acid ic m ateria l,

n on-acidic

sap o n ifiab le m ateria l,

and n e u t r a l n o n - s a p o n i f i a b l e m a t e r i a l . re c o v e re d a c i d i c and n o n - a c id ic re c o rd e d in T able I I . acetic

acid is

also

The am ounts o f

sap o n ifiab le m a te ria l are

The d e h y d r o g e n a t i o n o f t e t r a l i n - 2 -

recorded.

D e h y d r o h a l o g e n a t l o n o f 2 - b r o m o - l - t e t r a l o n e - 2 - a c e t 1c a c i d w as a l s o

in v e s tig a te d as a ro u te

l-n a p h th o l-2 -acetic and n o n -a c id ic

acid..

to

th e d e sire d

The am ounts c f re c o v e re d , a c i d i c

sap o n ifiab le m ateria l are also

recorded in

th e follo w in g ta b le . Summary o f a t t e m p t e d a r o r a a t l z a t i o n s o f l-tetralo n e-2 -acetlc

acid

T ab le I I R ecovered as acid ic m aterial

R ecovered as non-acld-ic sapon­ if ia b le m ateria l

S tarting- M a te ria l

M ethod

1 . l-te tra lo n e -2 a c e tic acid

Pd-C, t r i ­ al e t h y l b e n zene

45 0 mg.

tetra lin -2 a c e tic acid

?d~C, t r i ­ ethylben­ zene

none

la c to n e of l-t.etra lo n e -2 a o e tic acid

Pd-C, t r i ­ eth y lb en ­ zene

510 mg.

1 5 5 mg.

la c to n e of l-te tra lo n e -2 a c e tic acid

Pd-C, t r i ­ ethylben­ zene, then reflu x ed w ith a c e t i c anhydride

none

530 mg.

4 0 9 mg.

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.

108

R ecovered as a c id ic m ateria l

R ecovered as n o n -a c id ic . saoonif ia b le m aterial

S ta rtin g M aterial

M ethod

5.

2-brom o-ltetra lo n e -2 a c e tic acid

trle th y lam ine i n benzene

11? m

41 0 mg.

6 . 2-brom o-ltetra lo n e -2 a c e t i c S. c i d

dim ethylan illn c

65 mg,

4 1 5 mg.

?.

P otassium a c e ta te in ethanol

none

1 5 0 mg.

2-brom o-ltetra lo n e -2 a c e tlc acid

&