权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

SYNTHESIS OF URUSHI LIPID

漆脂的合成

基本信息

批准号：
62550678
负责人：
MIYAKOSHI Tetsuo
金额：
$ 1.22万
依托单位：
MEIJI UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1987
资助国家：
日本
起止时间：
1987 至 1988
项目状态：
已结题

项目摘要

Synthesis of urushiol was studied on the two process. One is the process which uses furan compound, and another process uses veratrole as starting material, respectively. The former process has no need for the protection of reactive hydroxyl groups of catechol ring, but it has a problem how to build catechol ring. The target of the study on this process is to find better precursor of urusiol. Fran compounds were used as starting materials forsynthsizing the precursor of urushiol. 5-substituted tetrahydrofuran compounds were treated through many steps such as electro-oxidation, hydrogenation and claisen condensation, etc, sequentry. Methyl 2,5-dimethoxyterahydro-2-froylacetate (I) is formed from methyl 2-furoate by these treatments, (I) reacted with alkyl halide in the presence of base catalysis and gave methyl alpha-(2,5-dimethoxytetrahydro-2-froyl)-slpha-alkylacetate(II). (II) is a precursor of urusiol and is converted to urushiol by hydrolysis. It became clear that the selection of solvent and alkyl halide had an influence on the yield of (II). Aprotic solvent and alkyl iodide gave good results.In another process using veratrole, the problems are, first, how to protect the reactive hydroxyl groups and how to retrieve them from protection. And second, how to build carbon skeleton of side alkyl group which has identical configuration with that of natural lipid. The results of the research on these problems indicates that the replacement of methoxy group of veratrole with acetoxy group enables ot aviod the side reactions accompanied with retrieval of hydroxylgroups. And the configuration of side alkyl or alkylene group is required to be coincident with that of natural urushi lipid stereochemically. It is practicable to synthesize carbon skeleton, by using wittig reaction, almost identical with natural lipid.

对这两种工艺合成漆酚进行了研究。一种是使用呋喃化合物的方法，另一种是分别使用藜芦醇作为起始原料的方法。前一种方法不需要保护邻苯二酚环上的活性羟基，但存在如何构建邻苯二酚环的问题。本研究的目的是寻找更好的漆酚前体。以弗兰化合物为起始原料，对漆酚前体进行了酯化反应。5-取代的四氢呋喃化合物经电氧化、氢化、克莱森缩合等多步反应后，再进行酯化反应。2-糠酸甲酯经上述处理生成2，5-二甲氧基四氢-2-甲酰乙酸甲酯（Ⅰ），（Ⅰ）在碱催化下与卤代烷反应生成α-（2，5-二甲氧基四氢-2-甲酰）-α-烷基乙酸甲酯（Ⅱ）。(II)是漆酚的前体，并通过水解转化为漆酚。很明显，溶剂和卤代烷的选择对（II）的产率有影响。在另一种使用邻苯二甲酸的方法中，问题是，首先，如何保护活性羟基以及如何从保护中恢复它们。第二，如何构建与天然油脂具有相同构型的侧链烷基碳骨架。对这些问题的研究结果表明，用乙酰氧基取代藜芦醇的甲氧基，可以避免羟基回收时的副反应。侧链烷基或亚烷基的构型要求与天然漆脂的构型在立体化学上一致。利用Wittig反应合成与天然油脂基本相同的碳骨架是可行的。