| 摘要 |
A general, efficient, and environmentally friendly method is provided for producing mostly beta-epoxides of DELTA5-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 5beta,6beta-epoxides of steroids from DELTA5-unsaturated steroids having a substituent at the 3alpha-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 DELTA5-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 5beta,6beta-epoxides with excellent beta-selectivities and high yields.
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