Conversion null to under (under 0 under 2 under ) --shirirueteru 7 under 1 under under -suteroido 1 under

摘要

The present invention is a process for conversion of Δ16-steroids (I), to the corresponding Δ17(20)-20-silyl ether (III), by reaction with (1) a preformed copper hydride or a metal hydride reducing agent in the presence of a copper species and (2) a silylating agent. The Δ17(20)-20-silyl ethers (III) are useful intermediates in the preparation of steroids useful as pharmaceuticals.