6,8-二甲基-5,7,4′-三羟基双氢黄酮合成的研究

6,8-二甲基-5,7,4′-三羟基双氢黄酮(Ⅴ,简称Farrerol)是从黑龙江省植物满山红(Rhododendron dauricum L.)叶中分离出的化痰有效成分之一。本文报道两种合成farrerol的方法:A法自2,4,6-三羟基-3,5-二甲基苯(Ⅰ)与对-乙氧羰基香豆酸酰氯(Ⅳ)进行Fries重排;环合反应,B法为化合物Ⅰ经2,4,6-三羟基-3,5-二甲基苯乙酮(ⅪⅤ)与对-羟基苯甲醛(Ⅻ)在乙二醇,硼酸中进行缩合。合成品farrerol为消旋体,与天然品的药理作用、毒性及临床效果一致。

Studies on the synthesis of 6,8-dimethyl-5,7,4'-trihydroxyl flavanone

Farrerol (Ⅴ) has been isolated from the leaves of Rhododendron dauricurn L. (Man-Shan-Hong) of Heilongjiang province. Its structure is ascertained s 6, 8-dimethyl-5,7,4′-trihydroxyflavanone, which is a phlegm-reducing principle.We report here two routes of syntheses for farrerol (Ⅴ). The first is condensation of compound Ⅰ with compound Ⅳ to give compound Ⅵ, followed by a Fries reaction and cyclization. The second route makes use of the condensation of compound (ⅩⅣ) with p-hydroxybenzaldehyde (Ⅻ) in the presence of boric acid using ethylene glycol as a diluent.Synthetic (±)-farrerol was found to be identical with the natural specimen by IR and NMR spectra. They were also comparable pharmacologically, toxicologically and clinically.