Studies of the Selective<i>O</i>-Alkylation and Dealkylation of Flavonoids. XIV. A Convenient Method for Synthesizing 5,6,7-Trihydroxy-3-methoxyflavones from 6-Hydroxy-3,5,7-trimethoxyflavones
作者:Tokunaru Horie、Hideaki Tominaga、Isao Yoshida、Yasuhiko Kawamura
DOI:10.1246/bcsj.66.877
日期:1993.3
acetonitrile afforded the 5,6,7-trihydroxyflavone as a main product without cleavage of the 4′-methoxyl group and the reaction was more conveniently applicable for the synthesis of the 5,6,7-trihydroxyflavones. The method, however, was not adapted to the synthesis of the flavones with methoxyl groups adjacent to the hydroxyl group on the B ring, since the benzyloxyl gro...
研究了 6-羟基-3,5,7-三甲氧基黄酮及其乙酸酯的去甲基化,并发现了以下结果。6-羟基-3,4',5,7-四甲氧基黄酮与 30% 无水氯化铝的乙腈溶液脱甲基反应得到 5,6-二羟基-3,4',7-三甲氧基黄酮和 5,6,7-三羟基的混合物-3,4'-二甲氧基黄酮,但其乙酸酯的去甲基化形成了 5,6,7-三羟基黄酮作为主要产物。后一反应可用作合成 5,6,7-三羟基-3-甲氧基黄酮的一般方法。另一方面,6-羟基-3,4',5,7-四甲氧基黄酮与 10% 无水溴化铝在乙腈中的脱甲基反应得到 5,6,7-三羟基黄酮作为主要产物,4'-甲氧基,该反应更适用于合成5,6,7-三羟基黄酮。