Multi-functionalization of gallic acid towards improved synthesis of α- and β-DDB

The synthesis of mono-, di- and trisubstituted gallic acids and their ester with similar or different groups including different acetal and ketals is described. Regioselective bromination on two ortho-positions of methyl gallate, which is very crucial for many organic syntheses, was achieved in high yield and purity. The α- and β-DDB were synthesized in high overall yield and purity from the regioselective bromoderivatives.