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The reactions of 7-methoxy-2-phenyl-2H-1-benzopyran and 7-methoxy-2-phenyl-4H-1-benzopyran with lead(IV) acetate gave 2-benzoyl-6-methoxybenzofuran and 6-acetoxy-3-methoxy-6-(3-oxo-3-phenyl-1 -propenyl)-2,4-cyclo-hexadien-1-one. The reactions of 7-methoxy-2-(p-methoxy-phenyl)-2H-1-benzopyran and 7-methoxy-2-(p-methoxyphen-yl)-4H-1-benzopyran with lead(IV) acetate also gave the corresponding benzofuran and cyclohexadienone. The reaction pathway is discussed.

The oxidation often 2-phenyl-2H-1-benzopyrans with potassium permanganate in acetone has been found to give the corresponding flavones in 8–73% yields. The reaction mechanism is discussed on the basis of the substituent effect and the oxidations of related compounds.