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
Epoxide-Initiated Cationic Cyclization of Azides: A Novel Method for the Stereoselective Construction of 5-Hydroxymethyl Azabicyclic Compounds and Application in the Stereo- and Enantioselective Total Synthesis of (+)- and (−)-Indolizidine 167B and 209D
作者:P. Ganapati Reddy、Sundarababu Baskaran
DOI:10.1021/jo035258x
日期:2004.4.1
and seven-membered epoxyazides 3b,c underwent smooth cyclization to give 5-hydroxymethyl azepine 4b and 5-hydroxymethyl azocine 4c, respectively, as a single detectable diastereomer. This novel methodology was elegantly applied in the stereoselective total synthesis of indolizidine alkaloids 167B and 209D. Further, the enantioselective total synthesis of natural and unnatural indolizidine alkaloids 167B