XY–ZH Systems as potential 1,3-dipoles. Part 51: Halogen-induced inter- and intra-molecular formation of nitrones from oximes and alkenes

Oximes possessing γ- and δ-alkenyl substituents are cyclised by N-bromo- or N-iodosuccinimide, iodine or ICl to the corresponding cyclic nitrones or their dimeric H-bonded hydroiodide salts in good yield; facially specific cycloaddition of these nitrones, and others derived by cyclisation of δ,δ-bis(alkenyl) ketoximes or by iodine induced addition of acetaldoxime to cyclohexene, furnish isoxazolidines.