The synthesis of etiojervane analogues of cortisone

The syntheses of C-nor-D-homo-cortisone 21-acetates (XIX and XVI), one of which possesses the cortisone configuration at each of the ring junctions has been described. Treatment of etiojerv-5-en-3β-ol-3,11-dione (III), obtained by degradation of jervine (I), with ethynylmagnesium bromide yielded stereoisomeric 17-ethynylcarbinols VII and VIII. Spectral and chemical studies show that (i) both the compounds possess C/D- trans and 13β-Me configurations and (ii) the 17-ethynyl group is oriented β in VII and α in VIII. Partial hydrogenation of VII in the presence of Lindlar catalyst gave rise to 17-vinylcarbinol XI, which on Oppenauer oxidation was converted into Δ 4 -3-ketone XIII. Compound XIII was then derived, by oxidation with osmium tetroxide followed by partial acetylation, into C/D trans - and C/D cis -fused 20,21-glycol 21-acetates XIV′ and XIV, although the former was not isolated in pure state. Oxidation of the acetates with Jones reagent led to formation of XIX and XVI, The configurational assignments for both compounds are based on spectral and chemical evidence.