Syntheses of 8-C-(1,1-dimethylallyl) Flavones and 3-methyl Flavonols

Abstract
8-(1,1-Dimethylallyl)-chrysin and 8-(1,1-dimethylallyl)-3-methylgalangin were synthesized in 70% and 73% yields, respectively, by sigmatropic rearrangement of 7-(3,3-dimethylallyl)-chrysin and 7-(3,3-dimethylallyl)-3-methylgalangin. The rearrangements were performed in a mixture of fused anhydrous sodium acetate and refluxing acetic anhydride as solvent.