| 摘要 |
<p>A general, efficient, and environmentally friendly method is provided for producing mostly ß-epoxides of Δ5-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 5ß, 6ß-epoxides of steroids from Δ5-unsaturated steroids having a substituent at the 3α-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 Δ5-unsaturated steroids, bearing different functional groups such as hydroxy, carbonyl, acetyl of ketal group as well as different side chains, were conveniently converted to the corresponding synthetically and biologically interesting 5ß, 6ß-epoxides with excellent ß-selectivities and high yields.</p> |
