Phenylselenyl halide induced formation of cyclic nitrones from alkenyl oximes

Abstract

Oximes possessing alk-γ- or -δ-enyl substituents are cyclised by phenylselenyl bromide, or by phenylselenyl chloride and an appropriate silver salt, to the corresponding cyclic nitrones; the seleno nitrones undergo facially specific cycloadditions with N-methylmaleimide, bis(alk-γ,δ-enyl) and bis(alk-δ,δ-enyl) ketones undergo regiospecific cyclisation and stereospecific cycloaddition to furnish spirocyclic products.