Photochemically induced mercuric oxide - iodine oxidation of some unsaturated steroid compounds

Abstract

Photochemically induced HgO/I2 oxidation of cholest-5-en-3α-ol (6) and cholest-5-en-3β-ol (7) afforded (Scheme 3) products arising from the corresponding alkoxy radicals (12, 13 and 14a,b) and from attack of the I2O intermediate at the olefinic double bond (epoxides 15a and 16a,b respectively). With cholest-5-ene-1α,3β-diol 3-acetate (8) and cholest-7-ene-3β,5α-diol 3-acetate (9) the HgO/I2 oxidation led to unresolvable complex mixtures (Scheme 5). With the same reagent cholest-5-en-3α-ol acetate (10) and cholest-5-en-3β-ol acetate (11) underwent exclusively attack by I2O, to give epoxides 20a,b, iodohydrin 21, and rearranged products 19 and 22 (Scheme 7), in the case of 10, and predominantly epoxides 23a,b (Scheme 8), in the case of 11. © 1994.