Highly stereoselective synthesis of steroidal 2,5-diketopiperazines based on isocyanide chemistry

Abstract

In this Letter we report that the Ugi reaction/cyclization sequence on a steroidal 17-carboxaldehyde leads to novel steroidal 2,5-diketopiperazines with a noteworthy stereoselectivity. A wide variety in the substitution pattern in the heterocyclic moiety was easily achieved by changing the components in the Ugi reaction. © 2009 Elsevier Ltd. All rights reserved.