Studies on Pumiliotoxin A Alkaloids: An Approach to Preparing the Indolizidinic Core by Intramolecular Dia­stereoselective N‐Heterocyclic Carbene Catalyzed Benzoin Reaction

Abstract

AbstractIn this article, we describe the development of a convergent organocatalytic strategy to prepare the indolizidinic core of the pumiliotoxin A alkaloid family. The key step of the proposed strategy is based on a diastereoselective N‐heterocyclic carbene catalyzed benzoin reaction, in which the Breslow intermediate generated from an enal moiety (umpolung a1 to d1 – acyl anion equivalent) attacks a ketone moiety intramolecularly to provide the indolizidinone core in good yield with good selectivity.