A partial synthesis of aldosterone

Abstract

Aldosterone was partially synthesised starting from adrenosterone by a multi-step reaction sequence. Hydrocyanation was applied successfully to a D-homo-Δ¹²-11-keto-steroid to furnish a 13β-cyano-11-ketone in highly stereoselective manner and in excellent yield. The 18 → 11β-lactonic function was readily derived from this cyano-ketone by a three-step synthesis, and the resulting olefinic lactone was transformed into the lactonic ketol acetate, the final product of the present synthesis, by D-ring contraction and by subsequent lengthening of the C-17 side-chain.