Cleavage of the Methylenedioxy Ring. III. Cleavage with Sodium Benzyloxide in Dimethyl Sulfoxide

Cleavage of the methylenedioxy ring in aromatic formyl (1-3), nitro (4 and 5), and acetyl (30) compounds with N-sodium benzyloxide-benzyl alcohol in dimethyl sulfoxide gave 3-hydroxybenzene derivatives (19, 22-24, 26, 27, and 33). In the case of the acetyl compound 30, the 4-hydroxybenzene derivative (34) was also obtained as a minor product. Regioselective cleavage of the ring in aromatic compounds having electron-withdrawing groups with nucleophilic oxide anions is discussed. Cleavage of the ring in 1-5 and 30 with 2N sodium methoxide in dimethyl sulfoxide-dimethylformamide was found to be useful for the praotical preparation of 3-hydroxybenzene derivatives (6-10 and 31).