Reactive intermediates. Part XX. Preparation of sulphoximides from sulphoxides and N-amino-lactams, and a study of their fragmentation

Abstract

Lead tetra-acetate oxidation of N-amino-lactams in the presence of sulphoxides gives sulphoximides in good yields. The sulphoximides undergo photochemical fragmentation to regenerate the sulphoxides and N-nitrenes, which can be intercepted by cyclohexene. Vapour phase pyrolysis at 400–500° also results in fragmentation of the sulphoximides, but under these conditions nitrogen is extruded from the heterocyclic systems, and products of ring contraction can be isolated. Thus, phthalimidosulphoximides give benzocyclobutene-1,2-dione.