Copper(II)-catalyzed [2,3]-sigmatropic rearrangement of N-methyltetrahydropyridinium ylids

Heath, P., Roberts, E., Sweeney, J.B., Wessel, H.P. and Workman, J.A. (2003) Copper(II)-catalyzed [2,3]-sigmatropic rearrangement of N-methyltetrahydropyridinium ylids. Journal of Organic Chemistry, 68 (10). pp. 4083-4086. ISSN 0022-3263 doi: 10.1021/jo034147v

Abstract/Summary

A ring-contractive and highly diastereoselective [2,3]-sigmatropic rearrangement occurs when N-methyl-1,2,3,6-tetrahydropyridine is treated with sub-stoichiometric amounts of copper or rhodium salts, in the presence of ethyl diazoacetate, giving ethyl cis-N-methyl-3-ethenyl proline (4).