1. A.V.Platonova, A.O.Layliev, S.N.Ananchenko, and I.V.Torgov,Bioorg.Khim, 1982,8, 542 [Sov.J.Bioorg.Chem.].
2. V.I.Zaretsky, inMass Spectrometry of Steroids, Israel University Press, New York, Toronto, 1976, 81.
3. T.R.Kasturi and J.Parvathis,J.Chem.Soc. Perkin Trans.1, 1980, 448.
4. W.A.Ayer, J.M.Browne, and S.Fung,Can.J.Chem., 1976,54, 3276; K.Gollnik and J.Schade,Tetrahedron Lett., 1966, 2335; A.R.Bell, R.E.Ireland, and L.N.Mandec,J.Org.Chem., 1966,31, 2536.
5. M.V.Dodonov, N.S.Pestovsky, and S.N.Ananchenko,Proc. VII Indo-Soviet Symposium on the Chemistry of Natural Products, 8?12 December, 1986, 48.