Photochemistry of N-phthaloyl derivatives of methionine

Article abstract of DOI:10.1016/0040-4039(93)85100-B

Photocarboxylation of N-phthaloyl derivatives of methionine sulfoxide 1b and methionine sulfone 1c was observed in acetone as the major reaction. For 1a a fast electron transfer initiated cyclization which leads to the bicyclization product 3 (X-ray structure)was observed in the sensitized photolysis. Direct photolysis of 1a leads preferentially to the tricylic product 4 and the decarboxylation product 5. The methionine methyl ester 6a-c showed electon transfer initiated cyclization (for 6a) and disproportionation (for 6b), whereas 6c proved to be photostable.