Total synthesis of pukeleimide A, a 5-ylidenepyrrol-2(5H)-one from blue green algae

Abstract

A total synthesis of pukeleimide A 5, a member of a rare family of naturally occurring 5-ylidenepyrrol-2(5H)-ones produced by the marine blue alga Lyngbya majuscula, is described. The synthesis is based on elaboration of the ylidenepyrrolone 11a from the maleimide 13a by a regioand stereo-selective Wittig reaction with ethoxycarbonylmethylene(triphenyl)phosphorane, followed by conversion of 11a into the amide 25, and oxidation of 25 with selenium dioxide.