| Abstract: | The visible light irradiated solutions of the 1-methyl-1-(1′-11-(β-aspartoyl-methyl ester-imino)]ethenyl]-ketal-1H,5H-pyrido3,2-a]phenoxazin-5-one ( 1 ) and the 1,5-dimethoxy-11-(β-aspartoyl-N-acetyl-methyl ester)-pyrido3,2-a]phenoxazine ( 2 ) 1], in methanol and acidic methanol, are examined. Both methanolic solutions undergo light induced transformation according to an opening of the phenoxazinone and phenoxazine systems, not reversible in darkness. On the contrary, 1 and 2 in methanol-acid solutions, under visible light irradiation, yield a solvent photoaddition, reversible in darkness. Some phototransformation products are examined and a plausible mechanism, for the reactions explanation, is suggested. |
