作者:Romain Dupont、Philippe Cotelle
DOI:10.1016/s0040-4039(00)02011-6
日期:2001.1
trimethoxyphenyl-2-hydroxypropenoic acids 1a–d gave mixtures of (E) and (Z) mono, di or trihydroxyphenyl-2-hydroxypropenoic acids 2a–d when treated with boron tribromide. The isomerisation proceeds during the work-up and depends on the duration of the hydrolysis and the number of oxygens on the aromatic ring. When the aromatic ring was substituted with a methoxy group at the ortho position, a cyclisation occurs
(Ž) -单,二或三甲氧基苯基-2- hydroxypropenoic酸1A-d得到(的混合物ë)和(Ž)单,二或三羟基苯基-2- hydroxypropenoic酸图2a-d时用三溴化硼。异构化在后处理过程中进行,并取决于水解的持续时间和芳环上的氧数。当芳环在邻位被甲氧基取代时,发生环化,并且可以获得3-羟基香豆素3和苯并呋喃-2-羧酸4。3-羟基香豆素3a 3-(2-甲氧基苯基)-2,3-环氧丙酸甲酯与三溴化硼的反应也几乎可以定量获得。