Preparation of 3beta, 16beta-dihydroxyandrost-5-en-17-one: stabilization of its alpha-ketolic group toward alkali by formation of a semicarbazone.
Alkaline hydrolysis of a 16beta-acetoxy-17-oxo steroid is accompanied by almost complete rearrangement of the product to a 16-oxo-17beta-hydroxy steroid. Hydrolysis can be achieved without rearrangement by 1) formation of a C-17 semicarbazone, 2) alkaline removal of the acetate group, and 3) removal of the semicarbazone group in the presence of pyruvic acid-acetic acid. By employing this technique, the title compound was obtained from its diacetate in a yield of 65%.
D000734:Androstenediols / Q000138:chemical synthesis*; D055598:Chemical Phenomena; D002621:Chemistry; D002855:Chromatography, Thin Layer; D006868:Hydrolysis; D009682:Magnetic Resonance Spectroscopy; D012664:Semicarbazones / Q000138:chemical synthesis
D000734:Androstenediols; D012664:Semicarbazones