A Mild Silver Salt-induced Oxidation of Dibromo-5-hydroxytropolones to Dibromo-p-tropoquinones

Article abstract of DOI:10.1246/bcsj.55.1659

The treatment of 3,6-dibromo, 3,7-dibromo, 4,6-dibromo-, and unsubstituted 5-hydroxytropolones with silver acetate in acetone gave the corresponding p-tropoquinones in good yields.When this reaction was carried out in protic solvents, some of these tropoquinones underwent further attack by solvent nucleophiles to give Michael-adducts or ring-contracted cyclohexadienones.