Photooxygenation of azines, ie, adamantanone azine (1) and benzonorborn-7-one azine (4), afforded in addition to the corresponding ketones, lactones derived from a carbonyl oxide intermediate via an electron transfer pathway. On the other hand, 4-substituted-1, 2, 4- triazoline-3, 5-diones (TAD) react with azine 1 to give a 1, 3-dipole, an azomethinimine intermediate as nitrogen analogue of a carbonyl oxide, which afforded the [2+ 3]- ...
