Steroidal analogues of unnatural configuration. Part III. Reactions of the Δ5-bond in 4,4,14α-trimethyl-19-nor-10α-pregn-5-ene derivatives
Abstract
The Δ5-bond of 4,4,14α-trimethyl-19-nor-10α-pregn-5-ene and related substances undergoes stereoselective attack with a variety of reagents. trans-Addition leads exclusively to 5α,6β-disubstituted products, while cis-addition favours α-face attack. Cleavage of the derived α- and β-epoxides also leads exclusively to 5α,6β-disubstituted products. It is demonstrated that a 6β-hydroxy-compound in the 19-nor-5α,10α-series undergoes intramolecular alkoxy-radical attack upon the 3-position.