Application of electrophile-mediated cyclisations to the synthesis of the hexahydroazepine ring system

Abstract

Allenic oxime 6 undergoes efficient Ag^I-catalysed cyclisation to give the hexahydroazepine-based nitrone 7; this reactive 1,3-dipole was subsequently trapped by styrene and N-methylmalemide to give the adducts 8 and 9 respectively.