Syntheses of Ring-substituted Flavonoids and Allied Compounds. XII. Synthesis of (±)-Fukugetin Heptamethyl Ether

抄録

3', 4', 5, 7-Tetramethoxyflavon-(8")-ylacetic acid (X), prepared from 2-hydroxy-4, 6-dimethoxyacetophenone (III) in five steps, was condensed with phloroglucinol dimethyl ether (XIV) by means of triphenylphosphine-carbon tetrachloride-triethylamine to give 3, 5-dimethoxyphenyl ester (XV), Fries rearrangement of wbich provided 8-(2"-hydroxy-4", 6"-dimethoxyphenacyl)-3', 4', 5, 7-tetramethoxyflavone (XIII). Condensation of the latter with anisaldehyde in the presence of potassium hydroxide in dimethyl sulfoxidemethanol, followed by cyclization with sulfuric acid afforded the flavonylflavanone derivative (II) identical with natural (±)-fukugetin heptamethyl ether.