Synthesis of 5,8-dihydroxy-6,7-dimethoxyflavones and revised structures for some natural flavones
作者:T Horie
DOI:10.1016/0031-9422(95)00070-n
日期:1995.7
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 1 H NMR and UV spectra. Four natural flavones proposed as 5,8-dihydroxy-6,7-dimethoxyflavones, must have other structures and three are shown to be the isomeric
摘要 以 2',5'-二羟基-3',4',6'-三甲氧基苯乙酮为原料,合成了 6 个 5,8-二羟基-6,7-二甲氧基黄酮和 3 个 8-羟基-5,6,7-三甲氧基黄酮。选择性O-烷基化和脱烷基化,黄酮和它们的异构体6-羟基黄酮之间的区别通过 1 H NMR 和紫外光谱得到澄清。四种天然黄酮被提议为 5,8-二羟基-6,7-二甲氧基黄酮,必须具有其他结构,其中三种被证明是异构的 5,7-二羟基-6,8-二甲氧基黄酮。从 Ageratum conyzoides 中分离出的黄酮被正确识别为 8-hydroxy-5,6,7,3',4',5'-六甲氧基黄酮,但从蜡菊中分离出的黄酮的结构被修改为异构体 7 -羟基-5,6,8-三甲氧基黄酮。