1,3-dipolar cycloaddition of cyclic alpha-methoxynitrones, derivatives of 2H-imidazole 1-oxide and 4H-imidazole 3-oxide

The reactions of cyclic aldo- and alpha -methoxynitrones of the 2H-imidazol e-1-oxide and 4H-imidazole 3-oxide series with isocyanates, phenyl isothloc yanate, N-phenylmaleimide, and dimethyl acetylene dicarboxylate were studie d. The reactions give the corresponding 1,3-dipolar cycloaddition products. 2,2-Dimethyl-4-phenyl-2H-imidazole 1-oxide does not enter into a similar r eaction with isocyanates or phenyl isothiocyanate.