Synthesis of 5,7-Dihydroxy-2',4',5'-trimethoxyisoflavone and Its 7-Methyl Ether (Robustigenin)

Article abstract of DOI:10.1246/bcsj.53.831

The treatment of 2,4,6-trihydroxy-2',4',5'-trimethoxydeoxybenzoin with benzyl chloride gave a dibenzyl ether.The condensation of the ether with ethyl formate, followed by the debenzylation of the resulting isoflavone, afforded 5,7-dihydroxy-2',4',5'-trimethoxyisoflavone, which was then converted into a pentamethoxyisoflavone.The partial demethylation of the pentamethoxyisoflavone gave 5-hydroxy-2',4',5',7'-tetramethoxyisoflavone, which was identical with natural robustigenin.