N-Phthaloyl cysteine derivatives 1a-d were photochemically transformed by elimination, decarboxylation, and via electron transfer cyclization to the products 2, 3, 4 and 6–8. The spin selectivities of singlet and triplet pathways were investigated in acetonitrile and acetone. The excited singlets were prone to elimination and γ-H abstractions (eg formation of 5) whereas the triplets cyclized to thiazinoisoindoles. This behaviour can be correlated ...
