Microbiological reduction of 8,14-seco-D-homo-Δ1,3,5(10),9(11)-estratetraen-3-ol-14,17a-dione methyl ether and stereochemistry of the compounds formed

1. The reduction of the methyl ether of 8,14-seco-D-homo-Δ1,3,5(10),9(11)-estratetraen-3-ol-14,17a-dione by yeast gave optically active 8,14-seco-D-homosteroids. 2. The configuration of the alcohols obtained by microbiological reduction was determined after their transformation into conformationally stable 9,14-spiroethers. 3. Both equatorial and axial S-alcohols are formed depending on the yeast strain used.