Photochemical Beckmann Rearrangements. Correspondence between Substituent Effect in Oximes and Oxaziridines

Article abstract of DOI:10.1021/jo00140a019

The relative migratory tendencies of hydrogen and aryl groups in the photochemical Beckmann rearrangement of benzaldoximes 2a-c were compared with those in the photochemical rearrangement of 2-alkyl-3-aryloxaziridines 3a-f.The migratory tendencies depended on the nature of the aryl substituent and were similar in 2a-c and 3a-c, implying that the photochemical Beckmann rearrangement proceeds through an oxaziridine intermediate.A similar order of migratory tendencies was not found in the tert-butyloxaziridines 3d-f, presumably because of steric effects.