Copper(II)-catalyzed [2,3]-sigmatropic rearrangement of N-methyltetrahydropyridinium ylids.
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).
Heath
Peter
P
Department of Chemistry, University of Reading, UK.
Roberts
Edward
E
Sweeney
Joseph B
JB
Wessel
Hans Peter
HP
Workman
James A
JA