Photochemistry of nitroso compounds in solution. X. The reaction pattern of photo-excited nitrosamides

The initial step in photolysis of alkyl N-nitrosamides 1 and 2 has been shown to be homolysis of the N—N bond, giving amidyl radicals and nitric oxide. Under the reaction conditions nitric oxide disproportionated, in part, to NO2 and NO3 radicals. The amidyl radicals abstracted hydrogen atoms inter-molecularly from the solvent as well as intramolecularly from the δ-carbon of the alkyl chain, but not from that of the acyl chain. The combined pathways lead to the observed products as shown in Schemes 1 and 2. By this photolysis, the functionalization at the unactivated δ-carbon site of the alkyl chain could be achieved in 55% yield.