A novel and highly stereoselective approach to aza-spirocycles. A short total synthesis of 2-epi-(+/-)-perhydrohistrionicotoxin and an unprecedented decarboxylation of 2-pyrones.

Abstract

[reaction: see text] A novel and highly stereoselective synthesis of aza-spirocycles is described. An application of this methodology is illustrated as a short and concise total synthesis of 2-epi-(+/-)-perhydrohistrionicotoxin with high diastereomeric control at the aza-spirocenter. An unprecedented decarboxylation of the 2-pyrone ring is observed in this total synthesis effort.