Mechanism of Ozonation Reactions - Advances in Chemistry (ACS

9 Mechanism of Ozonation Reactions

Downloaded by UNIV OF MISSOURI COLUMBIA on April 23, 2013 | http://pubs.acs.org Publication Date: June 1, 1972 | doi: 10.1021/ba-1972-0112.ch009

V . Feist's Ester RONALD

E. ERICKSON

and GARY D.

MERCER

University of Montana, Missoula, Mont. 59801

The

ozonation

of Feist's

ester yields

three

dicarbomethoxytetrahydrofuran-4-one thoxy-5-hydroxy-2-oxa-2,3-dihydropyran

NMR,

primarily

and infrared

is probably

through

and trapping

studies).

4,5-diwere

evidence

(mass,

compounds

product

A mechanism is

and

Structures

The last of these

ozonation

the initial step is formation stage, the breakdown

spectroscopic

spectra).

not a direct

(V).

2,3-

3,4-dicarbome-

(IV),

carbomethoxy-1-oxaspiro[2.2]pentane assigned

products:

(III),

(stoichiometry

is proposed

in

ozonide.

From

of a primary

which that

abnormal.

>Tphe structure of Feist's a c i d , l a , w a s d e t e r m i n e d w i t h c e r t a i n t y some 60 years after its p r e p a r a t i o n (1-6).

M o r e r e c e n t l y , the p r o p o s a l

that the o z o n a t i o n p r o d u c t of F e i s t ' s ester ( l b ) s h o w n to b e i n c o r r e c t ( 7 ) .

h a d s t r u c t u r e I I was

O u r i n i t i a l r e p o r t not o n l y s h o w e d t h a t no I I

w a s present i n a n y o z o n a t i o n of Feist's ester b u t offered c h e m i c a l a n d spectroscopic p r o o f for I I I as a m a j o r o z o n a t i o n p r o d u c t . RO—C^ Ο II RO-C

Η —

Ο II R O - C —

Ο CH

2

Ο

Ο

RO—C—C—C—C—CH

.

Ο.

HC \ HC-

I

I

COOR

I

Η la, R = H Ib, R = C H

Η

\

II

CH

2

/ -C Ο

RO

Ο

III

3

114 In Ozone Reactions with Organic Compounds; Bailey, P.; Advances in Chemistry; American Chemical Society: Washington, DC, 1972.

9.

ERICKSON A N D M E R C E R

Ozonation

115

Reactions

T h i s p a p e r is c o n c e r n e d w i t h t h e s t r u c t u r e p r o o f of e a c h of t h e major p r o d u c t s of the o z o n a t i o n of t h e m e t h y l ester of Feist's a c i d . O t h e r d a t a p e r t a i n i n g to t h e m e c h a n i s m of this u n u s u a l o z o n a t i o n are p r e s e n t e d , and

a m e c h a n i s m is h y p o t h e s i z e d .


Experimental Materials. Solvents w e r e t h e best c o m m e r c i a l grades a v a i l a b l e a n d w e r e n o t p u r i f i e d f u r t h e r . F e i s t s a c i d w a s p r e p a r e d b y t h e m e t h o d of Goss et al. ( 2 ) . T h e m e t h y l ester w a s p r e p a r e d i n t h e n o r m a l F i s h e r m a n n e r w i t h m e t h a n o l a n d s u l f u r i c a c i d . A d d i t i o n of w a t e r , ether ex t r a c t i o n , r e m o v a l of ether, a n d d i s t i l l a t i o n y i e l d e d a colorless l i q u i d ( b p 7 8 ° - 8 0 ° C at 1.5 m m H g ) w h i c h c r y s t a l l i z e d u p o n s t a n d i n g , m p 30 ° C (lit. v a l u e 3 0 ° C ) ( 8 ) . 2,3-DiCARBOMETHOXYMETHYLENECYCLOPROPANE-2,3d2.

The

methyl

ester of Feist's a c i d w a s specifically d e u t e r a t e d b y d i s s o l v i n g 5.0 grams of t h e ester i n 25 m l of d e u t e r o m e t h a n o l c o n t a i n i n g 0.5 g r a m s o d i u m m e t h o x i d e a n d a l l o w i n g t h e m i x t u r e to s t a n d f o r o n e d a y . A f t e r a d d i n g 40 m l of d i l u t e s u l f u r i c a c i d a n d e x t r a c t i n g w i t h t w o 2 0 - m l p o r t i o n s of m e t h y l e n e c h l o r i d e , a d i s t i l l a t i o n y i e l d e d 3.5 grams of t h e d i d e u t e r o c o m p o u n d . Its N M R s p e c t r u m s h o w e d o n l y t h e m e t h o x y protons ( singlet at δ = 3.63) a n d m e t h y l e n e protons ( s i n g l e t at δ = 5.53). Ozonations. T h e ozonations w e r e c a r r i e d o u t u s i n g a W e l s b a c h T - 2 3 ozonator at — 78 ° C i n m e t h a n o l , m e t h y l e n e c h l o r i d e , F r e o n 11, or acetone. N o changes i n p r o d u c t ratios o r o z o n e s t o i c h i o m e t r y w e r e n o t e d w h e n n i t r o g e n w a s u s e d as the o z o n e c a r r i e r . Isolation of Products. P r o d u c t i s o l a t i o n p r o v e d to b e e x t r e m e l y difficult. A t y p i c a l p r o c e d u r e i n v o l v e d t h e o z o n a t i o n of t h e ester (2.0 g r a m s ) i n 30 m l m e t h a n o l at — 7 8 ° C u n t i l t h e s o l u t i o n b e c a m e b l u e a n d a precipitate h a d formed. After flushing w i t h nitrogen, a n d a l l o w i n g the m i x t u r e to s t a n d o v e r n i g h t at —78°C., w e c o l l e c t e d 1.0 g r a m of p r e c i p i tate. T h i s w a s r e c r y s t a l l i z e d three times f r o m 15 m l of a n h y d r o u s ether to y i e l d I I I , m p 6 7 ° - 7 1 ° C ( l i t . 6 8 ° C ) . E v a p o r a t i o n of t h e first ether r e c r y s t a l l i z a t i o n r e s i d u e a n d s l o w c r y s t a l l i z a t i o n f r o m 1.5 m l of a n h y d r o u s ether y i e l d e d c o m p o u n d I V , m p 9 6 ° - 1 0 2 ° C [ c a l c u l a t e d f o r C H i O : C — 44.04, Η = 4.58, Ο — 51.8; f o u n d : C = 44.67, Η — 4.66]. C o m p o u n d V w a s i s o l a t e d b y o z o n a t i o n of t h e ester i n F r e o n 11 at — 78 ° C a n d a l l o w i n g t h e p r e c i p i t a t e w h i c h f o r m e d to s t a n d i n s o l u t i o n o v e r n i g h t . A f t e r the p r e c i p i t a t e w a s c o l l e c t e d i n a c o l d B u c h n e r f u n n e l ( t h e p r e c i p i t a t e melts b e l o w 0 ° C a n d w a s s h o w n to b e a m i x t u r e of I I I a n d I V b y N M R ) , t h e filtrate w a s e v a p o r a t e d a n d t h e l i q u i d r e s i d u e w a s d i s t i l l e d to y i e l d ( b p 9 5 ° - 1 0 0 ° C . , 1 m m ) a m i x t u r e r i c h i n V ( > 9 0 % a c c o r d i n g to N M R ) [ c a l c u l a t e d f o r C H O r > : C = 51.63, Η =* 5.34, Ο = 43.03; f o u n d : C = 50.24, 50.53, Η = 5.27, 5.29]. 8

8

0

7

1 0

Product Analysis. Q u a n t i t a t i v e analysis f o r e a c h of t h e p r o d u c t s of t h e o z o n a t i o n of F e i s t ' s ester w a s c a r r i e d o u t b y a n N M R m e t h o d ( V a r i a n H A 6 0 ) . T h e solvent f o r t h e o z o n a t i o n w a s e v a p o r a t e d in vacuo, a s u i t a b l e i n t e r n a l s t a n d a r d ( u s u a l l y tert-butyl benzoate), was added a n d t h e spectra w e r e d e t e r m i n e d a n d i n t e g r a t e d i n c h l o r o f o r m - d . A l l analyses w e r e r e p r o d u c i b l e to ± 1 0 % .

In Ozone Reactions with Organic Compounds; Bailey, P.; Advances in Chemistry; American Chemical Society: Washington, DC, 1972.

116

OZONE REACTIONS W I T H ORGANIC COMPOUNDS

Table I.

Important Ions in the Mass Spectra of III and I l i a ///

ΙΠα m / e (%

Assignment Ρ P-H 0 P-OCH P-CH3OH 2

3


P-C2H3O2

and P-C H and P-C H 2

2

{OCH CO}H 0 , CH 0, {C H 0 CHO}H 0 , CH OH

202 184 171 170 143

(2) (3) (9) (53) (73)

2

3

2

2

2

3

2

3

Assignment Ρ P-HDO P-OCH P-CH OD 3

3

P-C2H3O2

P-{OCH CO}D P-C2H3O2, C H 0 P-{C H 0 CDO}H P - C H 0 , CH2OD 2

113 (100)

2

3

m / e (% rel. abundance)

rel.

abundance)

2

2

111

(53)

2

3

3

2

2

204 (1) 185 (3) 173 (4) 171 (60) 145 (21) 144 (75) 115 (33) 114(100) 112 (63)

Results T h e structure of I I I was reasonably w e l l established i n l i m i n a r y c o m m u n i c a t i o n of this w o r k . A c o m p a r i s o n of its mass ( T a b l e I ) w i t h that of its d i d e u t e r o a n a l o g I l i a confirms its a n d p r o v i d e s a mass s p e c t r a l m o d e l for c o m p a r i s o n w i t h compounds I V and V . D H s C O O C - C ^ 1 H3COOC-C D

our pre spectrum structure unknown

,0, X

C H I C

2

0

III a T h e h i g h mass peaks i n T a b l e I c a n b e r a t i o n a l i z e d q u i t e easily. H o w e v e r , the ions of highest a b u n d a n c e at 143 a n d 113 i n I I I w h i c h at first glance c a n be assigned to f r a g m e n t a t i o n of a c a r b o m e t h o x y g r o u p are, f r o m i n s p e c t i o n of the d a t a f r o m I l i a , of m o r e c o m p l e x o r i g i n . C o m p o u n d I l i a h a d a p e a k at 145 as expected for loss of c a r b o m e t h o x y , b u t it also shows a n intense p e a k at 144 w h i c h m u s t c o m e f r o m the loss of { — O C H C = 0 } D . T h e d e u t e r i u m t h e o r e t i c a l l y c o u l d be transferred f r o m either t h e a or β carbons to either the keto or ether functions. N o n e of these rearrangements are p a r t i c u l a r l y f a c i l e a c c o r d i n g to the l i t e r a ture. T h e base peaks i n the spectra of I I I a n d I l i a ( 113 a n d 114 respec t i v e l y ) are also of interest. L o s s of c a r b o m e t h o x y a n d C H 0 , w h i c h appears to b e a l i k e l y f r a g m e n t a t i o n p a t t e r n , does not seem to o c c u r to a m a j o r extent for I l i a w h e r e the c o r r e s p o n d i n g 115 p e a k is present i n 2

2


9.

Ozonation

ERICKSON A N D M E R C E R

only 3 3 %

relative abundance.

117

Reactions

T h u s , a n o t h e r h y d r o g e n transfer, this

t i m e f r o m the m e t h y l e n e g r o u p to one of the o x y g e n atoms, m u s t t a k e place. T h e i n f r a r e d s p e c t r u m of I V i n d i c a t e s a n e n o l (3200 a n d 1650 c m " ) , 1

a n α,β u n s a t u r a t e d ester (1675 c m " ) , a n d a n o r m a l c a r b o m e t h o x y c a r 1

b o n y l g r o u p (1725 c m " ) .

T h e N M R s p e c t r u m substantiates t h e e n o l i c

1

character of the m o l e c u l e w i t h a singlet (δ •= 11.3 p p m ) . t w o d o u b l e t s ( ^ 4 . 4 0 a n d 4.84 p p m , / =

It also shows

16.5 c p s ) w h i c h c a n b e assigned


to t w o m e t h y l e n e protons ( s i m i l a r c h e m i c a l shift to analogous

protons

i n I I I ) , a n d singlets at 3.78 p p m a n d 5.16 p p m . T h e r a t i o of protons w a s s h o w n to be 1 : 1 : 1 : 6 : 1 i n the o r d e r g i v e n . S u c h a s p e c t r u m is consistent w i t h either the e n o l f o r m of I I I ( I l l b s h o w n b e l o w ) or w i t h s t r u c t u r e I V .

H cooc-cif ° o

Hscooc^

N

3

?

H COOC— Cs.

P*

H

1 2

I

I

/C =

C

H COOC

2

^cr

I

OH

3

. C H

3

0

Illb

H

IV

C o m p o u n d I V gave a p o s i t i v e p e r o x i d e test w i t h p o t a s s i u m i o d i d e i n m e t h a n o l a n d a n a l y z e d r e a s o n a b l y w e l l for t h e s t r u c t u r e s h o w n .

How

ever, i t w a s difficult to p u r i f y a n d d e c o m p o s e d u p o n s t a n d i n g , a n d w e b e l i e v e d that mass s p e c t r a l e v i d e n c e w a s necessary for its final s t r u c t u r e proof.

W e e x p e r i e n c e d some difficulty i n o b t a i n i n g p u r e d i d e u t e r o I V

b u t w e r e a b l e to o b t a i n a satisfactory m o n o d e u t e r o

compound by

ex

c h a n g e of the e n o l i c p a t t e r n w i t h methanol-ci. T a b l e I I c o m p a r e s

the

mass s p e c t r u m of I V w i t h that of the m o n o d e u t e r o d e r i v a t i v e . H C O O C 8

^(V

N

CH

Ο

I

H C O O C ^

I

3

I OD

Although

IVa the p a r e n t , p a r e n t - O H ( D ) , a n d p a r e n t - H 0 2

(HDO)

peaks g i v e strong c o r r o b o r a t i v e e v i d e n c e for I V a n d I V a as the correct


118

OZONE REACTIONS W I T H

Table II.

Important Ions in the Mass Spectra of IV and IVa IV

Ρ P-OH P-H 0 P-OCH3 P-COOCH P-C H 0 or C H 0

218 (4) 201 (1) 200 (3) 187 (1) 159 (100)

2


3

7

IVa

3

2


m / e (% rel. Assignment abundance)

Assignment

3

ORGANIC C O M P O U N D S

3

127

4

(44)

Ρ P-OD P-HDO P-OCH P-COOCH P-C H 0 P-C H 0 P-C H D0 or C H D 0

219 (4) 201 (2) 200 (3) 188 (1) 160 (100)

3

3

3

7

3

2

3

4

3

6

128

(17)

127

(25)

3

2

2

4

s t r u c t u r e for the h i g h m e l t i n g c o m p o u n d , i n t e r p r e t a t i o n of the c o m p l e t e mass s p e c t r u m is not s t r a i g h t f o r w a r d . F o r e x a m p l e , t h e base p e a k for b o t h I V a n d I V a is a c c o u n t e d for r e a d i l y b y a loss of c a r b o m e t h o x y , b u t t h e s e c o n d most intense m/e, pathways

127, m u s t arise f r o m at least t w o different

( n e i t h e r of w h i c h is o b v i o u s ) .

The accumulated

evidence

leaves l i t t l e d o u b t b u t t h a t I V is the correct s t r u c t u r e of the h i g h m e l t i n g product. T h e t h i r d c o m p o u n d to b e i s o l a t e d f r o m ozonations of Feist's ester w a s V . Its N M R s p e c t r u m w a s of p r i m e i m p o r t a n c e i n e s t a b l i s h i n g its structure. O t h e r t h a n t h e m e t h o x y s i g n a l at 3.67 p p m , the o u t s t a n d i n g feature of the s p e c t r u m w a s t h e presence of t w o sets of A B d o u b l e t s w i t h c h e m i c a l shifts f o r the f o u r protons at 3.33, 3.23, 2.90, a n d 2.72 p p m . T h e r a t i o of p e a k intensities w a s 6 : 1 : 1 : 1 : 1 for the five types of protons. I n t h e s p e c t r u m of the d i d e u t e r o d e r i v a t i v e , the A B p a t t e r n at h i g h field w a s n o t present, s h o w i n g t h a t these h i g h field protons w e r e those a to the c a r b o m e t h o x y Table III.

groups. Important Ions in the Mass Spectra of V and V a V m / e (% rel. abundance)

Assignment Ρ P-CH 0 P-OCH3 P-CH3OH P-C H 0 P-C H 0 , C H 2

2

3

2

3

2

2

Va

2

186 (0) 156 (2) 155 (11) 154 (12) 127 (100) 113 (40)


Assignment Ρ P-CH 0 P-OCH3 P-CH OD 2

3

P-C2H3O2

P-C H 0 , C H 2

3

2

2

188 (0) 158 (2) 157 (12) 155 (13) 129 (100) 115 (44)

T h e m a j o r features of the mass s p e c t r a of V a n d its d i d e u t e r o d e r i v a t i v e are p r e s e n t e d i n T a b l e I I I . A l t h o u g h w e w e r e u n a b l e to detect t h e p a r e n t p e a k for V , t h e r e a s o n a b l e assignments i n T a b l e I I , the s i m p l i c i t y


9.

ERiCKsoN AND M E R C E R

Ozonation

119

Reactions

of the N M R s p e c t r u m , a c o m p a r i s o n w i t h n o r m a l e p o x i d e c h e m i c a l shifts ( m e t h y l e n e signals at l o w e r field t h a n m e t h o x y s i g n a l s ) , a n d the a n a lytical

data

compound

argue

for

4 , 5 - d i c a r b o m e t h o x y - l - o x a s p i r o [2.2] p e n t a n e

as

V. Ο


II

T a b l e I V s u m m a r i z e s s o m e of the s p e c t r a l d a t a for the assignment of s t r u c t u r e to c o m p o u n d s I I I , I V , a n d V . T a b l e V shows the r e l a t i v e amounts of I I I , I V , a n d V f o u n d i n differ ent solvents u n d e r v a r i a b l e e x p e r i m e n t a l c o n d i t i o n s . K n o w l e d g e of the m a j o r p r o d u c t s of the o z o n a t i o n of F e i s t ' s ester does not l e a d i m m e d i a t e l y to a k n o w l e d g e of t h e m e c h a n i s m of the r e a c t i o n a l t h o u g h the n a t u r e of t h e p r o d u c t s m a k e s i t o b v i o u s

t h a t the

m e c h a n i s m is different f r o m t h a t of most ozonations. H o w e v e r , i n s p e c t i o n of T a b l e I V , i n w h i c h p r o d u c t ratios change w i t h changes i n c o n d i t i o n s a n d other types of e x p e r i m e n t s , a l l o w s us to r a t i o n a l i z e a reasonable m e c h a n i s t i c sequence. T h e m o s t i m p o r t a n t p o i n t s to n o t e a r e : ( 1 ) T h e e p o x i d e is not a p r i m a r y p r o d u c t ; b o t h the s t o i c h i o m e t r y a n d the t e t r a c y a n o e t h y l e n e experiments i n d i c a t e that i t is f o r m e d f r o m a t t a c k of a n i n t e r m e d i a t e o n u n r e a c t e d F e i s t ' s ester. F o r e x a m p l e , less t h a n 1 m o l e of o z o n e p e r m o l e of Feist's ester is r e q u i r e d for a l l o z o n a t i o n s — w i t h the less r e a c t i v e solvents, s u c h as m e t h y l e n e c h l o r i d e a n d F r e o n 11, the d e f i c i e n c y i n o z o n e r e q u i r e d is a p p r o x i m a t e l y e q u a l to the a m o u n t of e p o x i d e f o r m e d . A d d i t i o n of t e t r a c y a n o e t h y l e n e b e f o r e o z o n a t i o n results i n a n o z o n a t i o n of n o r m a l s t o i c h i o m e t r y w i t h n o e p o x i d e being formed. ( 2 ) I f the r e a c t i o n is s t o p p e d b e f o r e c o m p l e t i o n , t h e r e l a t i v e a m o u n t s of I V f o r m e d are g r e a t l y decreased. T h i s suggests to us t h a t the i n i t i a l o z o n a t i o n p r o d u c t has s e v e r a l m o d e s of d e c o m p o s i t i o n a v a i l a b l e , a n d that r e a c t i o n w i t h F e i s t ' s ester ( o r t e t r a c y a n o e t h y l e n e ) is m o r e r a p i d than unimolecular decomposition. ( 3 ) W e w e r e u n a b l e to mary ozonide ( 9 ) ] b y l o w a b o v e - m e n t i o n e d results a n d ester s t r o n g l y suggest t h a t a

detect a n i n t e r m e d i a t e [e.g., Criegee's p r i t e m p e r a t u r e N M R (to — 1 3 0 ° C ) ; y e t t h e t h e f a c t t h a t I V does n o t r e a c t w i t h F e i s t ' s h i g h l y r e a c t i v e i n t e r m e d i a t e does exist.


120

O Z O N E R E A C T I O N S W I T H ORGANIC

COMPOUNDS

Table I V .


Compound

C-H

Mp,

Spectral MW

°C

III

ΟδΗχοΟβ

67-71

202

IV

ΟδΗχοΟγ

96-102

218

V

CSHIOOÔ

liquid

186

° As reported i n Ref.

7.

W e h y p o t h e s i z e t h e f o l l o w i n g g e n e r a l r e a c t i o n scheme: H

C O O C .

3

C H

2

+

0

3

H3COOC la

N C

C N

P a t h a i n v o l v e s u n i m o l e c u l a r d e c o m p o s i t i o n of a n i n i t i a l (VI).

I t is i m p o r t a n t to n o t e that since o t h e r

ozonide

methylenecyclopropane

d e r i v a t i v e s , s u c h as 2 , 3 - d i m e t h y l m e t h y l e n e c y c l o p r o p a n e , d o not u n d e r g o r i n g o p e n i n g o f t h e c y c l o p r o p a n e r i n g , b o t h r i n g strain a n d t h e presence of t h e c a r b o m e t h o x y g r o u p s m u s t be necessary for s u c h a n u n u s u a l d e c o m p o s i t i o n of a n i n i t i a l o z o n i d e .

T h e f o l l o w i n g sequence r a t i o n a l i z e s


9.

ERICKSON AND

MERCER

Ozonation

121

Reactions

Data for III, I V , and V


Infrared,

NMR σ mult. (rel. intensity)

cm~i

1778, 1740, 1675, 1636

5.1d(l), 4.25d(l), 3.8e(6), 3.7d(l)

3200, 1725, 1675, 1600

1 1 . 3 8 ( 1 ) , 5.16e(l), 4 . 8 4 d ( l ) , 4 . 5 5 d ( l ) , 3.78s(6)

3080, 3030, 1720, 890, 865, 833

3.67sC6), 3 . 3 3 d ( l ) , 2.90d(l), 2.72d(l)

4.12d(l),

e

3.23d(l),

s u c h a n o c c u r r e n c e b y suggesting that a p a r t i a l n e g a t i v e charge is sta b i l i z e d b y the c a r b o m e t h o x y groups.

Just as the c o n v e r s i o n of V I to I V m a y b e a c o n c e r t e d r e a c t i o n w i t h o u t the i n t e r m e d i a r y a c t i o n of V I I , so p a t h w a y b m i g h t r e a s o n a b l y i n v o l v e either V I or V I I . C r i e g e e a n d G u n t h e r h a v e s h o w n that t e t r a c y a n o e t h y l e n e c a n c h a n g e the n o r m a l course of t h e o z o n a t i o n of alkenes b y r e a c t i o n w i t h e i t h e r a z w i t t e r i o n or t h e " p r i m a r y " o z o n i d e p r o d u c e d i n s u c h reactions (10).

W e h a v e no p r o o f as to w h e t h e r t e t r a c y a n o e t h y l e n e

reacts w i t h V I or V I I , a n d e i t h e r r e a c t i o n c a n b e e n v i s a g e d t o p r o d u c e I I I as i n p a t h w a y c.

W e are left w i t h t h e d i f f i c u l t y of e x p l a i n i n g t h e

r e l a t i v e l y h i g h y i e l d s of I I I i n some solvents l i s t e d i n T a b l e I V .

When

I I I , a t w o - o x y g e n p r o d u c t is f o r m e d , e i t h e r o x y g e n or some o t h e r o x i d i z e d


122

OZONE REACTIONS W I T H

Table V .

CH2CI2 CH3OH CH OH« F r e o n 11 Freon 1 1 Acetone Acetone-CH Cl Acetone-CH Cl ' b

2

2

2

2

c

d

Relative III 40 64 57 35 62 38 33 71

0.67 0.76 0.86 0.74 0.71 0.75 0.65 1.03

3


Relative Yields

Stoichiometry, moles Oz/moles I

Solvent

ORGANIC C O M P O U N D S

Yields,

%

IV

V

21 23 13 33 0 30 32 29

39 13 30 30 37 32 35 0

Reaction stopped after 60% of I had reacted. Reaction stopped after 34% of I had reacted. 75% C H 2 C I 2 by volume. Tetracyanoethylene (equimolar with I) added before reaction began.

a 6 c d

product must be produced.

W i t h o x i d i z a b l e solvents, s u c h as m e t h a n o l

or acetone, t h e most reasonable a s s u m p t i o n m i g h t b e that V I o r V I I reacts w i t h solvent to y i e l d I I I ( p a t h d ) , b u t w e h a v e n o d i r e c t p r o o f for such a n assumption. S t o r y et al. h a v e suggested that V I I I m i g h t b e t h e i m p o r t a n t i n t e r m e d i a t e i n t h e o z o n a t i o n o f Feist's ester ( I I ) .

VIII

I f this is the i n t e r m e d i a t e , other m e t h y l e n e c y c l o p r o p a n e s s h o u l d g i v e o z o n a t i o n p r o d u c t s s i m i l a r t o those f o u n d i n t h e o z o n a t i o n o f Feist's ester.

Since they do not a n d because o u r evidence indicates that t h e

e p o x i d e is n o t a p r i m a r y p r o d u c t , t h e m e c h a n i s m o f Story et al. does n o t seem t o a p p l y t o this r e a c t i o n .

Literature Cited 1. Feist, F., Chem. Ber. (1893) 26, 747. 2. Goss, F. R., Ingold, C. T., Thorpe, J. F., J. Chem. Soc. (1923) 123, 327.



Ozonation Reactions

123

9.

ERICKSON AND M E R C E R

3. 4. 5. 6. 7. 8. 9. 10. 11.

Ettlinger, M . G . , J. Amer. Chem. Soc. (1952) 74, 5805. Ettlinger, M . G . , Kennedy, F . , Chim. Ind. (1956) 166. Kende, A. S., Chim. Ind. (1956) 437. Bottini, A. T., Roberts, J. D . , J. Org. Chem. (1956) 2 1 , 1169. Erickson, R. E., Tetrahedron Letters (1966) 1753. Schwan, U . , Ph.D. thesis, Technische Hochschule, Karlsruhe (1958). Criegee, R., Rec. Chem. Progr. (1957) 18, 111. Criegee, R., Günther, P., Chem. Ber. (1963) 96, 1564. Story, P. R., Alford, J. Α., Ray, W . L., Burgess, J. R., Preprints, Div. Petro leum Chemistry, ACS (1971) 16, A13.

R E C E I V E D May 20, 1971. Supported by the Petroleum Research Fund, admin istered by the American Chemical Society.


COMPOUNDS


O Z O N E R E A C T I O N S W I T H ORGANIC


Mechanism of Ozonation Reactions - Advances in Chemistry (ACS

Recommend Documents