Cyclodehydrogenation of 3-Cinnamoyltropolones with 2,3-Dichloro-5,6-dicyanobenzoquinone

Abstract

Abstract 3-Cinnamoyltropolone and 3-(3-methoxycinnamoyl)tropolone were oxidized with 2,3-dichloro-5,6-dicyanobenzoquinone to give 2-phenyl- and 2-(3-methoxyphenyl)-4,9-dihydrocyclohepta[b]pyran-4,9-diones, while 2′-and/or 4′-methoxy-substituted 3-cinnamoyltropolones gave 2-arylmethylene-2H-3,8-dihydrocyclohepta[b]furan-3,8-diones.