1, 3-Dipolar cycloaddition between ethyl trifluoroacetoacetate and N-(benzylidene)methylamine N-oxide

Abstract

The 1,3-dipolar cycloaddition between ethyl trifluoroacetoacetate and N-(benzylidene)methylamine Noxide, performed in boiling toluene, leads regio- and stereo-selectively to an isoxazolidine, while the corresponding ethyl acetoacetate is found to be unreactive under the same conditions. On the other hand, α-trifluoromethylstyrene behaves as α-methylstyrene and affords two diastereoisomeric trifluoromethyl-substituted cycloadducts.