A novel sequence of radical rearrangements involving the 5-exo cyclisation of a 3-(methylenecyclopropyl)propyl radical

Abstract

Radical 10, generated from the corresponding imidazolethiocarbonyl derivative 3 or the phenyl selenide 4, rearranges in a six-step process to give the cyclohexene 5, after reduction; this rearrangement sequence includes the selective 5-Exo cyclisation of a (methylenecyclopropyl)propyl radical and opening of the intermediate cyclopropylmethyl radical to give a ring-expanded product.