Chemistry of Carbohydrate Aziridines

Abstract

Publisher Summary This chapter discusses the chemistry of carbohydrate aziridines, with emphasis being placed on surveying preparative methods and ring-opening reactions. Carbohydrate aziridines or epimines are derivatives in which an aziridine ring is fused to a pyranose or furanose ring or to an exocyclic part of a carbohydrate molecule. From the mechanistic point of view, the reported syntheses of carbohydrate aziridines are based almost exclusively on S N 2 intramolecular nucleophilic substitution. The nucleophile is a nitrogen-containing group, often free or an N -substituted amino group, which can be generated in situ by the reduction of an azido or cyano group, or by the Michael addition of amines to a double bond with appropriate substitution. The neighboring leaving group is typically an alkyl (aryl)sulfonyloxy group, or is generated in situ , which is the case with the Mitsunobu reaction. The aziridine-ring closure invariably proceeds with the inversion of configuration at the atom bearing the leaving group. The stereochemistry of S N 2 nucleophilic substitution strongly favors the antiperiplanar disposition of the participating groups in the transition state. This chapter describes the methods for the synthesis of carbohydrate aziridines. It also explains the general properties of carbohydrate aziridines and elaborates the reactions of carbohydrate aziridines.