A high-yielding, chemoselective approach to the steroidal 6@-hydroxy 2, 4-dien-l-one system is described by starting from the 4@-acetoxy-S&6@-epoxy 2-en-1-one derivative. The method allows some useful interconversions in the withanolide series such as the conversion of 4@-acetoxywithanolide E into withaperuvin C and the conversion of withaferin A into jaborosalactone. The transformation involves a palladium-mediated reductive ...
