Polymethoxyflavonoids (PMFs) possess important biological activities, notably as anticancer agents. Semisynthesis of a series of PMFs were performed by glycoside hydrolysis, dehydrogenation, bromination, aromatic nucleophilic substitution, O-methylation, dimethyldioxirane oxidation and regioselective demethylation, starting from abundant and inexpensive natural sources naringin and hesperidin. A new synthetic method for ...