Cyclodehydrogenation of 3-Isopropenyl- and 3-(1-Phenylvinyl)-tropolones to 8H-Cycloheptafuran-8-one Derivatives

Article abstract of DOI:10.1246/bcsj.53.745

3-(1-Phenylvinyl)tropolone (3b) was prepared by the hydrolysis of cycloadducts of 6-methyl-6-phenylfulvene with dichloroketene. 3-Isopropenyltropolone and 3b were treated with 2,3-dichloro-5,6-dicyano-p-benzoquinone or performic acid to give 3-methyl- and 3-phenyl-8H-cycloheptafuran-8-one, respectively.Reaction of 3b with hydrazoic acid afforded an unexpected 3-acetyltropolone.