Oxidation Reactions in 9a-Halosteroids by Jones Reagent

Current investigations guided to searching androstane derivatives with potential anabolic activity, weakly androgenic one directed us to synthesize 3b,11b-dihydroxy-9a-halo-5a-androstane- 17-ones (4a-c). These compounds were oxidized by Jones' Reagent at 0 o C obtaining a selective oxidation of the equatorial 3b-hydroxyl group. This behaviour could be explained by the high steric hindrance at the 11b-position, increased by the strong inductive effect of the halogen atom at C-9a over the electronic density of the H-11a.