ChemInform Abstract: Reactions of 3-Isopropenyl- and 3-Acetyltropolone with Quarternary Ammonium Tribromides

Treatments of 3-isopropenyltropolone with quarternary ammonium tribromides in tetrahydrofuran afforded 3-methyl-8H-cyclohepta[b]furan-8-one. The reactions in methanol–dichloromethane gave 7-bromo-3-methyl-8H-cyclohepta[b]furan-8-one. Bromination of 3-acetyltropolone with the tribromides in tetrahydrofuran produced 3-(bromoacetyl)tropolone, while the reaction in the methanolic solvent gave 7-bromo- and 5,7-dibromo-substituted 3-acetyltropolones. The brominations of 4′-hydroxyacetophenone were also carried out.