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

TABLE 1. Calculat ion Equat ions for Corn

Expe r imen ta l DM and Coeff icients of ~unds (I)- (V)

ColTl- pound Por ~expt, D

(I) (II) (Ill) (iv)

~ Solvent a v

CCI~ 22,215 0,295 CCI~ 20,505 0,323 CCI~ 20,582 0,306 CCI~ 16,7t9 0,336 C~I18 t0,590 0,392 CCIr i5,212 0,273 (v)

554,976 585,380 M4,M9 392,095 436,t t 8 4t t,537

5,t8 5,32 5,13 4,36 4,59 4,46 -

The common solution of these two equations gives the following values : m c o s 0 = 0.757; m sin 0 = 5.169, whence m = 5~22 D, 0 = 81o40 ' .

The obtained value of the group moment of the 4 ,4 ,5 ,5 - t e t r amethy l -2 -oxo-1 ,3 ,2 -d ioxaphospho lane r ing can be used to calcula te the DM of compounds with any substi tuent on the phosphorus a tom if the 4 , 4 , 5 ,5 - t e t r a - me thy l -2 -oxo- l , 3 ,2 -d ioxaphospho lane f r agmen t is p resen t in the molecu le . Due to the smal l d i f ference in the expe r imen ta l DM va lues , the common solution of the equations for (I) and 4 , 4 , 5 , 5 - t e t r a m e t h y l - 2 - p - t o l y l - 2 - oxo-1,3 ,2-dioxaphospholane (III) does not give a re l iab le solution. However , p rocess ing the exper imen ta l DM values of compounds (I)-(III) using the "s ta t i s t ica l vec to r " method given in [71 g ives a c lose value of m (5~20 D), 0 = 80 ~

We used the value of the found group DM to ca lcula te the moment of pinacol phosphorous acid. It proved that the gcalc for th is compound (5.17 D when m(H -~ P) = 0.36 D [2]) prac t ica l ly coincides with the exper imen ta l DM (5.16 D in CCI4). As a r e su l t , this indicates that the obtained value of m is re l iab le and can be used in the ca lcula t ions .

Fo r analogous phosphonates with s i x - m e m b e r e d phosphorus he t e rocyc i e s the addit ive scheme sa t i s f ac - tor i ly d e s c r i b e s the exper imen ta l DM. The 2 -oxo-2 -pheny l - and 2 -oxo -2 -p -ch lo ropheny i -1 ,3 ,2 -d ioxaphos - phor inanes (IV) and (V) were synthesized by us . It was es tabl ished by x - r a y that (IV) has the cha i r f o r m with an equator ia l P =O group [81. However , a study of the IR spec t r a , and a l so of the tH and 31p NMR spec - t r a , d isc losed that (IV) ex i s t s in CCI 4 solution as two i somer i c f o r m s A and B.

~ H ~L(~o.~P--C6H4--X-P P

CH~ ,t~ C t t 3 ~ ~ / I H.. "

CH~ C|t3 u A B

x = It (IV); X =Ct (v)

S t ruc tu res A and B dif fer both as r e g a r d s the 6 31Pvalues in the NMI~ spec t r a ( respect ively --14 and --10 ppm re la t ive to 85% H31~ 4) and the va lues of the v p = O f requenc ies in the IR spec t ra (1260 and 1285 cm-1) . In this connection the ra t io of the A and B i s o m e r s is ~0.65 : 0.35, i . e . , the i s o m e r with an axial P = O group p redomina te s . A s i m i l a r conclusion follows f rom a study of the PMR spec t rum of (IV}, in which the i so mer i c s t r u c t u r e s di f fer in the va lues of the chemica l shif ts of the CH 2 protons (6, ppm, J, Hz}: for A) 6He = 4.23,

3JpH = 6, 6Ha = 3.75, 3Jla H = 17; for B) 6He = 4.42, JPH = 6, 6Ha = 3.65, 3JpH = 17. The r e su l t s of the

spec t ra l s tudies a re in good a g r e e m e n t with the l i t e ra tu re data [9,10].

The p re sence of an equi l ibr ium in (IV) and (V) is a l so conf i rmed by a study of the i r DM; it is quite mobile and changing the solvent leads to a change in the ra t io of the A and B f o r m s that take par t in the equi l i - b r i um (see Table 1). The c o n f o r m e r with an axial P =O group p redomina tes in both compounds . In ca lcu la - ting the DM of the 1,3,2--dioxaphosphorinane compounds we used the DM of the O --* P (0.60), P ~ O (2.95), and C H 2 - - O (1.10 D) bonds, given in [11, 12]; for (IV), PA =4.11 , PB = 5.93 D, and for (V), PA =4.50, PB =

5 . 5 6 D .

E X P E R I M E N TA L

The IR spec t r a were m eas u red on a UR-20 ins t rument . The IH and 3tp NMR spec t r a were r e spec t ive ly m e a s u r e d on a Var i an -60 HA s p e c t r o m e t e r and on an ins t rument that opera ted at v 0 = 9.86 MHz, equipped with an a t t achment for r ecord ing the 31 p isotope.

Compounds (I)-(V) were synthesized as desc r ibed In [13].

1912

Pinaco[ Pheny[phosphonate (I). mpl08-110 ~ Found: C 60.07; H 7.05%. C12H1703P. Calculated: C 60.00; H 6.67%.

PinacoI p-Chlorophenylphosphormte (II). mp 114-115% Found: C 51.86; H 5.35%. C12H1603PCI. Cal- oulated: C 52.55; H 5.84%.

Pinacol p-Tolylphosphonate (III). mp 77-79 ~ Found: C 60.74; H 7.55%. C13HlsO3P. Calculated: C 61.42; H 7.48%.

5,5-Dimethyl-2-oxo-2-phenyl-1,3,2-dioxaphosphorinane (IV). mp 104-105 ~

5,5-Dimethyl-2-oxo-2-p-chlorophenyl-1,3,2-dioxaphosphorinane (V). mp 109-110 ~ Found: C 49.95; H 5,47%; CnH1403PCI. Calculated: C 50.77; H 5.38%.

CONCLUSIONS

i. We were the first to determine the group dipole moment of the 4,4,5,5-tetramethyl-2-oxo-l,3,2- dioxaphospholane ring, which is directed toward the exocyclic bond of phosphorus at an angle of 81 ~

2. The 5,5-dimethyl-2-phenyl-2-oxo- and 2-p-chloropheny l-2-oxo-1,3,2-dioxaphosphortnane s exist in solutions as a c onformational equilibrium of the forms with an equatorial and axial P =O group, with~redom- ~ iaaace of the latter.

LITERATURE C I T E D

1. L . S . Khaikin and L .V. Vilkov, Usp. Khim., 41, 2224 (1972). 2. R . P . Arshinova, Usp. Khim., 4.6, 1544 (1977). 3. ~ . A. Ishmaeva, M. Vitchak, M. Mikolaichik, and A. N. Pudovik, Izv. Akad. Nauk SSSR, Set. Khim.,

1976, 1880. 4. V . I . Minkin, O. A. Osipov, and Yu. A. Zhdanov, Dipole Moments in Organic Chemistry [in Russian],

Khimiya (1968), p. 77. 5. ~ . A. Ishmaeva, M. G. Zimin, R. M. Galeeva, and A. N. Pudovik, Izv. Akad. Nauk SSSR, Ser. Khim.,

1971, 538. 6. ]~. A. Ishmaeva, F. M. Kharrasova, A. P, Zav'yalov, and A. N. Pudovik, Izv. Akad. Nauk SSSR, Ser.

Khim., 197._!1, 619. 7. H . F . VanWoerden and E. Havinga, Rec. Trav. Chim., 86, 341 (1967). 8. K . C . G, Killean, J. J. Lowrence, and L. M. Magennis, Acta Cryst. , B27, 189 (1971). 9. J. P~ Majora[, R. Pu)ol, J. Navech, and F. Mathis, Tetrahedron Lett., 1971, 3755.

10. A. Dale, Acta Chem. Scand., 2._66, 2985 (1972). 11. ]~. A. Ishmaeva, M. A. Pudovik, S. A. Terent'eva, and A. N. Pudovik, Dok[. Akad. Nauk SSSR, 19_.66,

630 (1971). 12. M . J . Aroney, L. H. L. Chin, R. J. W. LeFevre, and J. D. Saxby, J. Chem. Soc., 1964, 2948. 13. E . L . Getter, Organophosphorus Monomers and Polymers [in Russian], Izd. AN SSSR (1960).

1913