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.

[reaction: see text] 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.