Syntheses of the Marine Metabolites Verongamine, Hemibastadin-2, and Aerothionin Using the Cyano Ylide Coupling Methodology

Syntheses of the marine metabolites verongamine, hemibastadin-2, and aerothionin have been accomplished by a methodology involving the conversion of a carboxylic acid to an acyl cyano phosphorane which may be oxidized to an α,β-diketo nitrile. This strongly electrophilic intermediate is rapidly converted by amines to α-keto amides.