Oxaziridines provide useful alternatives to the Beckmann rearrangement and Schmidt reaction for ring enlargement of cyclic ketones. The procedure involves the condensation of the ketone in question with optically active a-methylbenzylamine, oxidation of the resultant imine, and photolysis to afford ring-expanded lactams. The a-phenylethyl substituent can be removed after photolysis to yield the N-unsubstituted lactam. When a distal ketone ...
