Hydroboration of steroidal-1,5-dien-3.BETA.-ols: A general procedure for the introduction of a hydroxyl group at 1.ALPHA.-position of the 3-oxygenated steroids.
Process for 1.alpha.,3.beta.-dihydroxy-.DELTA..sup.5 -steroids
申请人:Hoffmann-La Roche Inc.
公开号:US04305881A1
公开(公告)日:1981-12-15
A process for the synthesis of 1.alpha.,3.beta.-dihydroxy-.DELTA..sup.5 -steroids from steroids such as 1.alpha.,2.alpha.-epoxy-cholesta-4,6-dien-3-one, which is reacted with lithium in liquid ammonia in the absence of a proton donator and subsequently reduced by repeated alternative additions of a proton donator, said additions being followed in each case by an equivalent amount of lithium. The final product, a 1.alpha.,3.beta.-dihydorxy-.DELTA..sup.5 -steroid, is useful in the synthesis of derivatives of cholecalciferol.