A Novel and Highly Stereoselective Approach to Aza-Spirocycles. A Short Total Synthesis of 2-epi-(±)-Perhydrohistrionicotoxin and an Unprecedented Decarboxylation of 2-Pyrones

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.