PHOTO-OXYGENATION OF AZIRIDINES AND SOME POTENTIAL AZOMETHINE YLIDES

Sensitized photooxygenations of a few bicyclic aziridines and some potential azomethine ylides have been investigated. The photooxygenation of 1 -cyclohexyl-6- (cyclohexylimino) - la-phenylindano [1, 2- 5] aziridine (7) gave a 51% yield of 2-cyclohexyl-3-hydroxy-3-phenylphthalimidine (12). The photooxygenation of endo-2, 4, 6-triphenyl-1, 3-diazabicyclo[3.1.0]hex-3-ene (13), on the other hand, gave a mixture of products consisting of benzaldehyde (16, 5%), benzoic acid (5, 16%), and benzamide (19, 7%). Other substrates that we have examined include 2, 3-dihydro-5, 6-diphenylpyrazine (22), cis-2, 4, 5-triphenylimidazoline(33a), and 4-benzoyl-3-cyclohexyl-5-(cts-l, 2-diphenylvinyl)-2-phenyloxazoline (42). The photooxygenation of 22, for example, gave a 22% yield of 1, 3-dibenzoylurea (32), whereas 33a, under analogous conditions, gave a mixture of products consisting of 2, 5, 5-triphenylimidazolin-4-one (40, 7%), dibenzamide (36, 8%), and benzamide (19, 21%). The photooxygenation of42 gave a mixture of products consisting of benzoic acid (5, 52%) and N-cyclohexylbenzamide(45, 19%), whereas the direct photolysis of 42 under nitrogen atmosphere gave a 65% yield of3, 5, 6-triphenyl-2H-pyran-2-one (50). Reasonable mechanisms have been suggested for the formation of the different products in these reactions. © 1979, American Chemical Society. All rights reserved.