Photocyclisation of aroyl-1,4-quinones as precursors for anthracyclones and heteroanthracyclones

While pursuing our studies on the synthesis of anthracyclinones and heteroa nthracyclinones. We have studied the photocyclisation of benzoyl-1,4-benzoq uinones leading to xanthones and phenyl gentisate esters. To the best of ou r knowledge this is the first observation of photo-xanthone synthesis. Some mechanistic aspects of the reaction have been presented.