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

Grimes possessing gamma- and delta -alkenyl substituents are cyclised by N- bromo- or N-iodosuccinimide, iodine or IC1 to the corresponding cyclic nitr ones or their dimeric H-bonded hydroiodide salts in good yield; facially sp ecific cycloaddition of these nitrones, and others derived by cyclisation o f delta,delta -bis(alkenyl) ketoximes or by iodine induced addition of acet aldoxime to cyclohexene, furnish isoxazolidines. (C) 2001 Elsevier Science Ltd. All rights reserved.