SELECTIVE α-CLEAVAGE IN PHOTOLYSIS OF 7-SUBSTITUTED-6,9-DIMETHYL-6,7,8,9-TETRAHYDRO-6α,9α-EPOXYBENZOCYCLOOCTENE-5,10-DIONE

Article abstract of DOI:10.1246/cl.1982.653

Photolysis of the title compounds in benzene gave spirophtalides and E- and Z-alkylidene phtalides via preferential α-cleavage at the more crowded side.On the basis of quantum yields and triplet lifetimes, this preference is indicated to arise from the different efficiences of the radical recombination of possible biradicals.