β-胡萝卜素的合成工艺改进

Improved Method of Wittig-Horner Reaction for the Synthesis of β -Carotene

采用Wittig Horner法合成β 胡萝卜素,以3 甲基 5 (2,6,6 三甲基 1 环己烯 1 基) 1,3(或1,4) 戊二烯膦酸二烷基酯直接与2,7 二甲基 2,4,6 庚三烯 1,8 二醛反应合成目标产物,收率60%,与JamesH.Bable所申请的专利(US:4916250,1990)的方法相比不但省掉了一步碱催化的双键重排反应,而且收率提高10%。1HNMR,IR,MS显示与对照品一致。

β -Carotene was synthesized by Wittig-Horner reaction.3-Methyl-5-(2,6,6-trimethyl-1-cyclohexen-1-yl)-1,3(or 1,4)-pentadienylphosphonate reacted directly with 2,7-dimethyl-2,4,6-octatriene-1,8-dial to give the desired product in 60% yield.Compared with the literatures,not only the step of base-catalyzed double bond migration was curtailed but also the yield was improved by 10%.~1HNMR,IR and MS showed that the desired product was identical with criterion.