TRANSFORMATIONS PHOTOCHIMIQUES d'ENDOPEROXYDES DERIVES d'HYDROCARBURES AROMATIQUES POLYCYCLIQUES-I; CAS DU PHOTOOXYDE DE DIPHENYL-9,10 ANTHRACENE; OBTENTION ET PROPRIETES DU DIEPOXYDE ISOMERE

Article abstract of DOI:10.1016/S0040-4020(01)98961-6

When irradiated at long wavelengths (λ>=435 nm), the 9,10-endoperoxide of 9,10-diphenylanthracene 1a isomerizes to the 4a,10:9,9a-diepoxide 4a, which can be isolated at low temperature.On warming at 20-25 deg C, 4a gives only the benzocyclobutenic diether 6a by electrocycling ring opening and cyclisation, whereas under irradiation it undergoes, degradation to 10-hydroxy-10-phenyl-9-anthrone 7a and isomerizations to the bicyclic acetal 8a and to the benzofuro<3,2-b>benzofuran 9a.These transformations of 4a explain previous results obtained when irradiating 1a under various conditions; their mechanisms are discussed.