Stereochemical control–-nitrones from oximes by 1,3-azaprotio cyclotransfer or 1,2-prototropy
作者:Colm O'Mahony、Frances Heaney
DOI:10.1039/cc9960000167
日期:——
Oximes 1a,b and 10 are configurationally stable at elevated temperatures, the (E)-oximes react exclusively via a concerted 1,3-azaprotio cyclotransfer reaction to give 6- and 7-membered cyclic dipoles, respectively, whilst their Z-isomers react via a 1,2-prototropy-cycloaddition sequence furnishing fused isoxazolidines.