Synthesis of a bicyclic model for the marine hepatotoxin cylindrospermopsin

Abstract

A double Michael addition of ammonia to dienone 9 to give piperidinone 10 and the reaction of diamine 16 with isothiocyanate 19 to give protected guanidine 18 are the key transformations in a ten-step synthesis of the cylindrospermopsin model 22. © 1995.