Acid-induced rearrangement of cycloadducts from N-aryl itaconimides and 1,3-diphenylisobenzofuran

Treatment of several Diels-Alder adducts of N-aryl itaconimides and 1,3-diphenylisobenzofuran with a strong acid triggers a skeletal rearrangement resulting in 2-aryl-6,10b-diphenylbenzo[h]isoquinoline-1,3(2H,10bH)-diones.