Six 5, 8-dihydroxy-6, 7-dimethoxyflavones and three 8-hydroxy-5, 6, 7-trimethoxyflavones were synthesized from 2′, 5′-dihydroxy-3′, 4′, 6′-trimethoxyacetophenone by adapting the selective O-alkylation and dealkylation, and the differentiation between the flavones and their isomeric 6-hydroxyflavones was clarified by 1H NMR and UV spectra. Four natural flavones proposed as 5, 8-dihydroxy-6, 7-dimethoxyflavones, must have ...