A Convenient New Synthesis of 17-Azasteroids. Preparation of Some Novel N-Chloro-17-aza- and N-Chloro-17a-aza-17a-homosteroids as Potential Affinity Labels and Enzyme Inhibitors

Abstract

An efficient new synthesis of 17-azasteroids in the estrane and androstane series was developed from readily available 16.17-seco 17-carboxylic acid precurson by means of a diphenylphosphoryl azide-mediated Cunius rearrangement as the key step.Several novel N-chloro-17-aza-and N-chlom-17a-aza-17a-homosteroids were prepared from the corresponding lactams with N-chlorosuccinimide.Azasteroids frequently exhibit interesting biological activity and many such compounds are known.'The synthesis of new derivatives and the development of improved methods for their preparation is therefore of interest.We recently reportedZ the synthesis of several N-chloro derivatives of azasteroid lactams, which have potential utility as thiophilic affinity labels and enzyme inhibitors.Since the 17-position of steroid hormones