High-Order Use of Reactive Intermediates Stabilized by Oxygen Atom

氧原子稳定的反应中间体的高阶使用

基本信息

批准号：
05671752
负责人：
FUJIOKA Hiromichi
金额：
$ 1.09万
依托单位：
Osaka 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：
1993
资助国家：
日本
起止时间：
1993 至 1994
项目状态：
已结题

项目摘要

In this project, we studied on high-order use of i) the reactive intermediates in Beckmann fragmentation reaction and ii) the dioxenium cations formed by acid treatment of orthoesters.i) The Beckmann fragmentation is one of the long-known reactions and used widely in organic synthesis. Although the reactive intermediates in the Beckmann fragmentation of the corresponding alpha-alkoxycycloalkanone oxime derivatives are very active electrophiles, only a limited kind of nucleophiles such as H2O,ROH,halide anion and carbon ones have been used so far. As the organic synthesis utilizing the intermediates of Beckmann fragmentation, we developed new carbon-carbon bond forming reactions using silicon-containing carbon nucleophiles and organoaluminium reagents. As an extention of the reactions, we also succeeded in developing a novel asymmetric carbon-carbon bond formation by combination of Beckmann fragmentation reaction and asymmetric synthesis using a chiral acetal and a highly stereoselective carbon-carbon bond formation in the reaction of 2,3-isopropyridenedioxycyclohexanone oxime esters with organpaluminium reagents.ii) Orthoesters work as superior electrophiles by forming dioxenium cations We succeeded in a facile one-pot formation of oxacyclic compounds in the reaction of triols with trialkyl orthoesters in the presence of acid catalyst. The reaction was successfully applied to the unprotected high-order alcohols giving polysubstituted tetrahydrofurans in a one-pot synthesis.

在这个项目中，我们研究了i）贝克曼裂解反应中的反应中间体和ii）原酸酯酸处理形成的二氧鎓阳离子的高阶使用。i）贝克曼裂解是长期已知并广泛使用的反应之一在有机合成中。尽管相应的α-烷氧基环烷酮肟衍生物的贝克曼断裂中的反应中间体是非常活跃的亲电子试剂，但迄今为止仅使用了有限种类的亲核试剂，例如H2O、ROH、卤阴离子和碳阴离子。作为利用贝克曼裂解中间体的有机合成，我们利用含硅碳亲核试剂和有机铝试剂开发了新的碳-碳键形成反应。作为反应的延伸，我们还通过贝克曼断裂反应和使用手性缩醛的不对称合成相结合，成功开发了一种新型的不对称碳碳键形成，以及在2,3-反应中形成高度立体选择性的碳碳键。异丙吡啶二氧基环己酮肟酯与有机铝试剂。ii) 原酸酯通过形成二氧鎓阳离子作为优异的亲电子试剂，我们成功地实现了简单的一锅法形成在酸催化剂存在下，三醇与三烷基原酸酯反应生成氧杂环化合物。该反应成功应用于未保护的高级醇，在一锅合成中得到多取代的四氢呋喃。