A kinetic study of the acid-catalyzed rearrangement of the title compound (6) to form 5, 8- dihydroxy-4, 4-dimethyl-l (4H)-naphthalenone (4) in dioxane-water, ethanol-water, and ethanol-dioxane is reported. In water mixtures the presence of 4-acetyl-2, 5-dihydroxy-3, 3- dimethyl-2, 3-dihydrobenzo [blfuran (7) is detected, and it slowly leads to the rearrangement product 4. The rate constant of the transformation 6-4 is more than 1Wfold faster than 7-4, ...