NOVEL ENEL REACTIONS OF TETRACYANOETHYLENE WITH STEROID & DIENES

Recently-described work1 on the ene-reaction between acrylonitrile and ergosteryl acetate to give the adducts (I-III) leads us to report our investi-gation of some unusual reactions of tetracyanoethylene with three steroidal cisoid dienes. Tetracysnoethylene reacted rapidly with ergosteryl acetate in benzene solution to give a 1:l adduct, C H N 0 36 46 4 2,* * m.p. 135", [al, 25-170 " in 65 % yield. We suggest the structure (IV) for this compound. The adduct was extremely labile, readily decomposing with-loss of hydrogen cyanide to give intractable colored products under acidic or basic conditions or in protic solvents. The lability of the compound suggested that an ene-addition product rather than a Diels-Alder adduct had been formed (cf. ref. 1 and papers cited-therein), and detailed support for structure (IV) was given by the highly characteristic spectra of the compound. The U.V. cyclohexane spectrum [hmax 213 mp (~8080)] indicated a A- 5,8(14) diene system. 192 In the n.m.r. spectrum*** the three vinyl protons at C-6, C-22, and C-23 gave a multiplet signal at T 4.80-4.92 [cf. (I), C-6H at T 4.58,- C-22H and C-23H at 7 4.773.l At T 5.43 the spectrum of IV showed a sharp one-proton singlet, superimposed on a broad one-proton multiplet assigned to the C-3 proton. The singlet is ascribed to the isolated 2'-proton. A doublet at z 6.42 (J = 4 c./sec.) was assigned to the C-7 allylic proton. This coupling constant indicates that the C-7 proton is quasi-axial with respect to the C-6 vinyl proton and thus that the tetra-cyanoethyl side-chain is 7a-, corresponding to the situation in (I-111).1 A *To whominquiries should be addressed. **All new compounds described gave satisfactory elemental analyses.-xx *N. m. r. spectra were taken in CDCl 3 solution