Epoxide-Initiated Electrophilic Cyclization of Azides:  A Novel Route for the Stereoselective Construction of Azabicyclic Ring Systems and Total Synthesis of (±)-Indolizidine 167B and 209D

A novel and general method for the stereoselective construction of 5-hydroxymethyl azabicyclic ring skeletons based on epoxide initiated electrophilic cyclization of azides has been developed and applied in the synthesis of (±)-indolizidine 167B and 209D with an overall yield of 16.5% and 17.8%, respectively. The efficiency of this methodology is further exemplified in the synthesis of azepine skeleton via tandem cation−olefin−azide cyclization.