Photochemical transformations of tropolones. Part II. 4′,5′-Dimethoxy-6,7-benztropolone methyl ether and its photo-oxidation
Abstract
Irradiation of 4′,5′-dimethoxy-6,7-benztropolone methyl ether in aqueous ethanol under nitrogen yielded an isomeric tricyclic ketone. When the irradiation was carried out under oxygen, the main products were two γ-lactones. Their structures have been interrelated and the structure of one of them confirmed by the synthesis of its dihydro-derivative.