The procedure of Ercoli and Ruggieri (Gazz. Chim. Ital. 84, 312, 1954, incorporated herein by reference) was followed to prepare 20-cyano-20-hydroxy-4-pregnene-3-one (I-25) from progesterone. Thus, the suspension of progesterone 1.2 g in acetone cyanohydrin 2.4 ml was stirred and warmed at 40° C. until all the progesterone was dissolved. Four drops of triethylamine was then added. After 2 h the precipitate was filtered and dried to give crude I-25 1.4 g; m.p. 188°-90° C. After recrystallization from ethanol (contained 1% acetic acid), the product was obtained as fine crystals, m.p. 199°-200° C. The mixture containing cyanohydrin (I-25) 0.4 g, methane sulfonyl chloride 1 ml and pyridine 5 ml was stirred at room temperature for 5 h, then at 80° C. for 1 h. Water 20 ml was added and the precipitate was collected. The crude product was chromatographed on silica gel TLC plate (developed by hexane:/ethyl acetate, 1:1). The yield of I-26 was 80 mg, m.p. 195°-6° C.
