Abstract 17β-Acetyloxy-3-methoxy-6-(phenylsulfonyl) estra-1, 3, 5 (10), 6-tetraene (4) was prepared as a substrate for conjugate addition of organolithium reagents by a three-step sequence starting from 17β-acetyloxy-3-methoxyestra-1, 3, 5 (10)-trien-6-one (2). While methyllithium showed only poor face selectivity, higher alkyllithium species (n-BuLi, t-BuLi) preferred to add to the β-face of 4. 7α-Substituted derivatives, on the other hand, were ...
