Total synthesis of 3,3′,4-tri-O-methylellagic acid from gallic acid

Total synthesis of 3,3′,4-tri-O-methylellagic acid has been described from commercially available gallic acid. Construction of the crucial unsymmetric Ar–Ar bond has been carried out in various methods such as Heck coupling, Heck coupling followed by oxidation or anionic Fries rearrangement, Suzuki cross-coupling, etc., but all the attempts were unsuccessful. Then, finally it has been achieved by intramolecular Ullmann coupling reaction.