Method for synthesizing 5beta, 6beta-epoxides of steroids by a highly beta-selective epoxidation of delta5-unsaturated steroids catalyzed by ketones

摘要

A general, efficient, and environmentally friendly method is provided for producing mostly &bgr;-epoxides of &Dgr;⁵-unsaturated steroids using certain ketones as the catalyst along with an oxidizing agent, or by using certain dioxiranes. In another aspect of the invention, a method is provided for producing mostly 5&bgr;,6&bgr;-epoxides of steroids from &Dgr;⁵-unsaturated steroids having a substituent at the 3&agr;-position by an epoxidation reaction using a ketone along with an oxidizing agent under conditions effective to generate epoxides, or using a dioxirane under conditions effective to generate epoxides. A whole range of &Dgr;⁵-unsaturated steroids, bearing different functional groups such as hydroxy, carbonyl, acetyl or ketal group as well as different side chains, were conveniently converted to the corresponding synthetically and biologically interesting 5&bgr;,6&bgr;-epoxides with excellent &bgr;-selectivities and high yields.