and up to 10-15% of the corresponding diaryl disulfide was detected in the reaction mixture. At the end of the indicated time the ESI (IVa-c) were treated with the appropriate nuc[eophile.

Acetoxy adducts (Va-c) were obtained by adding to a solution of the appropriate ESI at --50 ~ a mixture of 0,5 g of MeCOOK and 0.5 m[ of MeCOOH in 5-7 m[ of the solvent used to obtain (IV), cooled to --50 ~ After 10 rain the temperature was raised to ~20 ~ and 30 mI of saturated aqueous NaHCO~ solution was added, after which the mixture was extracted with 2 • 100 m[ of ether, and the extracts were washed with water and dried over Na~SO 4. After evaporation of the ether the residue was purified by TLC. The character is t ics of (Va-c) are given in Table 1.

Methoxy adduct (Via) was obtained by treating (IVa) as described in [7]. The PMR spectrum was [den- t[ca[ with that described in [7].

C O N C L U S I O N S

The opening of S-ary[episu[fonium complexes that are isobutylene derivatives proceeds with the exclu- sive formation of the Markovnikov adducts.

1,

Q

3. 4.

5.

6 .

7. 8.

L I T E R A T U R E C I T E D

G. H. Sehmid and D. G. Garrat t , "Eleetrophilic additions to carbon- -carbon double bonds," in: The Chemistry of Double Bonded Functional Groups (ed. by S. Patai). Wiley, New York (1977). G. H. Schmid and D. G. Garrat t , Can. J. Chem., 51, 2463 (1973). W. H. MueIler and P. E . Butler , J. Am. Chem. S.c., 90, 2075 (1968). W. A. Stair, A. S. Gybin, V. S. Bogdanov, M. Z. Krimer, and l~. A. Vorob'eva, Tetrahedron Lett., 12, 1085 (1978). A. S. Gybin, M. Z. Krimer, V. A. Smit, V. S. Bogdanov, and l~. A. Vorob'eva, Izv. Akad. Nauk SSSR, Ser. I~him., 1978, 510. G. Olah, P. Westerman, Eo Me[by, and Y. Mo, J. Am. Chem. S.c. , 96, 356.5 (1974). M. Oki, W. Nakanishi, M. Fukunaga, G. Smith, W. Duax, and Y. Osawa, Chem. Lett., 1975, 1277. Y. Kikuzono, T. Yomabe, S. Nagata, H. Kato, and K. Fukui, Tetrahedron, 30, 2197 (1974)o

E F F E C T OF N A T U R E OF S U B S T I T U E N T S ON

P H O T O C H E M I C A L B E H A V I O R OF

2 , 6 - D I S U B S T I T U T E D 1 , 4 - B E N Z O Q U I N O N E S

B . D . S v i r i d o v , L . P . G r y z u n o v a , V. M. K u z n e t s , G. A . N i k i f o r o v , K. De J o n g e , H. J . H a g e m a n , a n d V. V~ E r s h o v

UDC 541.14:547.567

The effect of the nature of the substituents on the photochemical behavior of the 2,6-dimethy[- (I), 2,6- di - ter t -butyl- (II), and 2,6-diphenyl-l,4-benzoquinoncs (IIi) in protic and ap t . t i c solvents was studied in the present paper. A partial study of the behavior of the given objects in photochemical processes was made previously [1-3], but the inadequacy of the photolysis conditions did not permit making a comparative estimate of the effect of structural factors on the character is t ics of the photochemical t ransformations.

The photolysis of the studied quinones in a[iphatic alcohols leads to various reduction products (Table 1).

Institute of Chemical Physics, Academy of Sciences of the U SSR, Moscow. L. Ya. Karpov Physicochemi-- ca[ Institute, Moscow. AKZO Research Laboratories, Arnhem, Netherlands. Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 9, pp. 2160-2163, September, 1978. Original article submitted January 27,

1978.

1908 0568- 5230/78/2709-1908 $07.50 �9 1979 Plenum Publishing Corporation

T A B L E 1. Compos i t i on of Pho to lys i s P r o d u c t s of 2 ,6 -Disubs t i tu ted 1 ,4 -Benzoqu inones in V a r i o u s Media

Solvent

MeOH EtOH

(Me~) CHOH

(Me3)COH

MeCOOH

Ph-Me

CsH~

C6F~

2,6-Dimethyl- 2~6-DiAtert-butyl - 2.6-Diphenyl- time, ] prod- h [ uets

i ,o (IV) o,5 (iv)

0,5 (IV)

22 (IV)

yi, ld, ! timc,[ % !h iproduets

0 2,5 0 3,0

0 3,5

0 6,5

3,0

i3,0

i3,0

i3,0

(VII) (V)

(VII) (V)

(r162 (vii) (vi) (IX) (v)

(vi) (v)

(vi) (v)

(vI)

yield, time, % h

62 I0

37 52 75 * 25 t4 * 36 113 * 66

B,0 ~,0

7,5

i L0

3,0

],0

3,0

3,0

prod- acts

(viii) (VUI)

(VUI)

(VIII)

(VIII) (X) (X)

(X)

(X)

yield %

92 t00

95.

90,

78 i2

t00

iO0

*The conversion of the quinone was 20~o, and the yield was based on reacted quinone.

0 OH Me II Me Me ] Me

"(7 ,0 H o OH

(1) (iv) 0 OH 0---~M~, OH

R I] I! R ] R R | [ R [ CHoC(Me~)OB

0 "0 \ + I t , / + 0 OH OH OH

(ll) (V) (VI) (VII) B = t-Bu

Ph ![ Ph Ph

IE ] 0 OH (III) (VIII)

As can be seen f r o m Table 1, the na tu re of the subst i tuent has an i m p o r t a n t e f fec t on the c h a r a c t e r of the p r o d u c t s obtained by the pho tochemica l r educ t i on of 2 ,6-d isubs t i tu ted 1 ,4 -benzoqu inones with a l coho l s . The s t e r i c e f f ec t s of the subs t i tuen t s a r e the r e a s o n fo r the i n c r e a s e in the n u m b e r of end r e a c t i o n p roduc t s when Me is r ep l aced by the t - B u g r o u p . Compounds with an i s o m e r i z e d t - B u g r o u p [(VI), (VII)] a r e f o r m e d p redominan t ly h e r e . This is c o n f i r m e d by the E PR s p e c t r o s c o p y data , which t e s t i fy to the absence of a t - B u g r o u p in one of the o pos i t ions of the r i ng . The photolys is of (III) in a i iphat ic a l coho l s leads to the f o r m a t i o n of one r e d u c t i o n p roduc t , the d ibenzofu ran de r iva t ive {VIII), in high y ie ld . It is no t ewor thy that fo r (I) and {III) the y ie ld of t he i r sole photo lys i s p r o d u c t s , (IV) and (VIII), is independent of the na ture of the a lcohol was is d e t e r m i n e d only by the i r r ad i a t i on t i m e , which is m a x i m u m in the c a s e of t -BuOH~ The compos i t i on and r a t i o of the pho to lys i s p r o d u c t s of {II) now depend on the na ture of the a l coho l . Thus , the a p p e a r a n c e of s u b - s tant ia[ amoun t s of hydroquinone (V) is obse rved when the pho to lys i s of (II) is run in a l coho l s tha t p o s s e s s high r educ t i on p r o p e r t i e s {ethyl and i sopropyD; up to 40% of cyc l i c compound (VI), which is absent in all of the o ther c a s e s , is f o rmed in t -BuOH. The y ie ld of hydroquinone (VII) i n c r e a s e s s y m b a t i c a l i y with i n c r e a s e in the ac id i ty of the a l coho l . The la t t e r fac t could s e rve as c o n f i r m a t i o n of the t heo ry e x p r e s s e d in [4] tha t (VI) and (VII) a r e f o r m e d via the i n t e rmed ia t e o - s p i r a n s t r u c t u r e .

o R ~ ( ~ -Me2 ~otl/[ll +]

~ x ~ - ~ (vI) + (vii)

Otl

1909

However , the data that we obtained when the photolysis of (II) is run in AcOH cont rad ic t th is theory : a mix ture of products (VI) and fiX) was obtained, in which connection the la t te r is the e s t e r analog of (VII) and its yield does not exceed 50%.

OH R I CHzC(M~)OCOMe

(II) h';(AcOS)(VI)-t- X~)//~x I OH

37% (IX), 52%

The photolysis of (III) in AcOH a l so y ie lds two products : the d ibenzofuran der iva t ive (VIII), which can be cons idered to be the reduct ion product , and the d i m e r of the s ta r t ing quinone (X).

0 0 hv (AtOlt) P h ~ Ph

(lID )' (VIII} + 78%

(x}, i9.%

It is noteworthy that the long i r rad ia t ion of d l m e r (X) g ives a mix tu re of the s ta r t ing quinone (III) and dibenzofuran (VIII). Consequently, it may be a s sumed that a substant ia l amount of (VIII) in the reac t ion m i x - lu re is assoc ia ted with the low light stabil i ty of d l m e r (X).

The photolysts of (II) and (III) in a roma t i c hydrocarbons (toluene, benzene , hexafluorobenzene) gives an even more dis t inct re la t ionsh ip between the composi t ion of the products and the nature of the subst i tuents in the r ing. Thus, if only reduct ion products (V) and (VI) a r e fo rmed when {I1) is i r rad ia ted in the indicated so l - vents , then the photolys is of (IH) gives d t m e r (X) in quanti tat ive yie ld . Here the photolysis of (III) p roceeds quite rapidly (3 h) and the convers ion is comple te , whereas quinone (II) is photolyzed only to the extent of 20% in 13 h of i r rad ia t ion . Since toluene p o s s e s s e s c l ea r ly exp re s sed reduct ion p r o p e r t i e s , then, as was to be expected, the yield of hydroquinone (V) is m ax imum (75% when based on reac ted quillone) when the photoiysis of flI) is run in toluene. The absence of reduct ion products when (III) is i r rad ia ted in toluene is possibly assoc ia ted with the low act ivi ty of the excited t r ip l e t s ta te of qulnone (III). The re su l t of th is is i ts g r e a t e r tendency to d i m e r i z e .

The re la t ive ly easy i somer i za t i on of (IID indicates that " s te r ie cont ro l" m a k e s it poss ib le for two ex - cited t r ip le t molecu les of the quinone to converge to the dis tance needed to fo rm the cyclobutane ring (<4.3 [5]). This is only possible if the plane of the phenyl subst i tuents coincides with the plane of the quinoid r ing , in which connection the d i m er i e de r iva t ive (X) is evidently a syn-adduct of the "head to head" type . Replacing the Ph groups in the quinone by the bulky t -Bu groups [quinone flI)] does not pe rmi t the molecu les to converge to a dis tance sufficient to f o r m the cyclobutane r ing, and only reduct ion p r o c e s s e s a re poss ib le when the photolysis of (II) is run tn a r o m a t i c hydroca rbons .

A noteworthy fact when the photolysis of (II) is run in PhCH3, C6H 6, or C6F 6 is an inc rease in the yield of the cycl ic der iva t ive WI) ( respect ive ly 25, 36, and 66% when based on r eac ted quinone). The fo rmat ion of (VI) and an inc rease in i ts yield when the photolysis of (II) is run in C6H 6 or C6F 6 unequivocally t e s t i f i e s to the p r o g r e s s of e i ther in t r amotecu la r r eac t ions of the excited molecu les of quinone (II) or ln t e rmolecu la r i n t e r ac - t ions of the excited s tate of the quinone with the unexcited s ta te .

The m e c h a n i s m of the photochemical t r a n s f o r m a t i o n s of the indicated quinones will be studied by us in a

subsequent pape r .

EX PERIMENTAL

The solut ions of quinones (I)-(HI) (~2 .1 0 -2 m o l e / l i t e r ) in al iphat ic a lcohols , AcOH, and a roma t i c h y d ro - ca rbons were blown with argon fo r 30 min and then i r rad ia ted with the light (k > 310 nm) f rom h i g h - p r e s s u r e Hg lamps (DRSh-1000), with s t i r r ing by a magnet ic s t i r r e r . The reac t ion cou r se was checked via the TLC data on Silufol p la tes . The i r rad ia t ion t ime and the y ie lds of the reac t ion products a r e indicated in Table 1. The spec t ra l c h a r a c t e r i s t i c s of (V)-(X) cor respond to the data given in [4, 61. On comple t ion of the photolysis of (II) in a lcohols and AcOH the solvent was removed and the res idue was ch romatographed (TLC) on LSL-254 s i l ica gel in the s y s t e m hexane -- e ther (50:50 by volume) . The EPR spec t rum of (VII) r e p r e s e n t s a quintet with a spli t t ing of 1.8 Pc . In the case of the a r o m a t i c hydroca rbons the TLC was run on L s i l ica gel in the sy s t em b e n z e n e - - e t h e r (90:30 by volume) . On complet ion of the photolysis of (III) in AcOH the solvent was

1910

dist i l led off and e ther was added to the r e s idue . The obtained c r y s t a l s of (X) were s epa ra t ed . The mother l iquor was eh romatographed ( T I C ) on LSL-254 s i l ica gel in the s y s t e m hexane - - e the r (30:70 by volume) . The phototysis of 0.1 g of d i m e r (X) in C6H 6 was run in a s im i l a r manner , with an i r rad ia t ion t ime of 5 h~ We obtained 0.03 g of (III) [100% when based on reac ted (X)].

C O N C L U S I O N S

1. We studied the photochemical t r a n s f o r m a t i o n s of some 2,6-disubst i tu ted 1,4-benzoquinones in a l i - phatic a lcohols , acet ic acid , and a r o m a t i c hydroca rbons .

2~ In al iphatic a lcohols the photolysis of the quinones leads to the fo rmat ion of only reduct ion products , whereas in ace t ic acid and a rom a t i c hydrocarbons the nature of the subst i tuents e x e r t s a substant ia l effect on the s t ruc tu re of the end reac t ion products .

1~ 2. 3.

4~ 5. 6~

L I T E R A T U R E C I T E D

A. V. E l ' t s ov , O. P. Studzinskii , and V. Mo Grebenkina, Usp~ Khim., 46, 185 (1977). Ho J. Hageman, Methoden der Organ i schenChemie , Vol. 4 /5b , pho tochemie (1976), p. 941. S. Patai (editor), The Chemis t ry of Quinonoid Compounds, Vol. 1, Hebrew Univers i ty , J e r u s a l e m , I s r a e l (1974). Co M. Orlando, J r . , H. Mark , ,4. K. Bose , and M. S. Manhas , J . A m . Chem. Soc., 89, 6257 (1967). Do l~abinovich and G, M. J . Schmidt, J . Chem~ SOCo, B!967, 144. H. J~ Hageman, Chem. Commun~ 196___99, 837.

DIPOLE MOMENTS AND STBUCTUBE OF SOME

CYCLIC PHOSPHONIC ESTERS

]~. A o I shmaeva , V. V. Ovchinnikov, and A. N. Pudovik

UDC 541.67:541.63:547.1 '118

A study of cycl ic e s t e r s us ing the method of dipole momen t s (DM) is g rea t ly hindered due to the need of knowing the i r s t e r i c s t ruc tu re and the m o m e n t s of the individual bonds. The data on the s t e r i c s t ruc tu re of f i v e - m e m b e r e d phosphorus he t e rocyc le s a r e ambiguous [1]. The DM of the bonds involving the phosphorus a tom a l so change [2]. A compar i son of the exper imen ta l data for s e v e r a l untypical compounds, which p o s se s s a di f ferent polar i ty but have the same s t e r i c s t r u c t u r e , is helpful in such c a s e s . In calculat ing the i r t h e o r e t i - cal DM it is expedient to use the group m om en t s of the f r a g m e n t s , for which accura t e s t ruc tu ra l and bond u a r a m e t e r s a r e lacking. In pa r t i cu la r , the need was shown in [3] of using the group m o m e n t s of the 1,3,2- dioxaphospholane r ings in view of the nonaddit ive contr ibution made by the CH3 group to the DM of the m o l e - cute .

In the presen t communica t ion we used the method given in [4] to de t e rmine the group momen t of the ~_~e(o)

f r agment , s ta r t ing with the exper imen ta l DM of the phenyl- (I), p -ch lo ropheny l - (II), and pinacol p - to ly lphos - uhonates (III). In the calcula t ion we used the DM of the Csp 2 --* P (0.39), H ~ Csp 2 (0.70), CH 3 ~ Csp2 (1 .06)

and C s o z -.. CI (0.89 D) bonds, given in [5' 6]; the exper imenta l DM and coeff ic ients of the calculat ion equa-

t ions a r e given in Table 1.

The DM vec to r of P - - A t - - X - p was oriented along the X axis , white the unknown group momen t of the 4 ,4 ,5 ,5 - t e t r ame thy l -2 -oxo-1 ,3 ,2 -d ioxaphospho lane r ing (m) was d i rec ted toward it at an angle of 0. Fo r the studied compounds the calcula t ion equations have the fo rm:

~t~expt (I) = m ~ cos 2 0 ~- 1.t88--2.180m cos 0 Jr m 2 sin20 ~xpt ( I I ) = m ~ cos ~ 0 + 0.250 + m cos 0 + m z sin 2 0

Vo Io U l ' yanov-Len in Kazan State Un ive r s i t y . Trans la ted f rom Izves t iya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 9, pp. 2164-2166, September , 1978. Original a r t i c le submit ted F e b r u a r y 17, 1978.

0568-5230/78/2709-1911507.50 �9 Plenum Publishing Corpora t ion 1911