Steroid Total Synthesis, Part VIII; (+)‐estr‐4‐ene‐3,17‐dione

Abstract

Abstract A novel synthesis of the title compound, involving the resolution of a Mannich base derived from racemic 11,11‐ o ‐phenylenedioxy‐7‐hydroxy‐1‐dodecen‐3‐one is described. In an alternate approach 2( S )‐acetamido‐6,6‐ o ‐phenylenedioxy‐heptanoic acid was used as the optically active starting material. This scheme features the preparation of a chiral 1,2‐epoxide and its regiospecific alkylation with lithio‐1, 1‐diethoxy‐2‐propyne.