Imines, RCH= N-ZH, possessing a range of ZH groups (Z= CHCOPh, CHCOSR, CHCONHR, CHP (O)(OEt) 2, 2-CH-pyridyl, 2-CH-thiazolyl, and 9-fluorenyl) undergo thermal 1, 2- prototropy generating azomethine ylides stereospecifically. The intermediate azomethine ylides undergo cycloaddition reactions with dipolarophiles either via an endo-transition state or via both endo-and exo-transition states to give polyfunctional pyrrolidines in good yield. ...
