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Studies on the reactions of chiral dianions

手性二价阴离子反应的研究

基本信息

批准号：
62470021
负责人：
TANIKAGA Rikuhei
金额：
$ 3.52万
依托单位：
Kyoto University
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (B)
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

Chiral b-hydroxysulfones (I), -hydroxysulfones (II), and -hydroxy-nitrocompounds (III) were prepared in 100% e.e. by Baker's yeast reduction of the corresponding ketones. Reduction of chiral -ketosulfoxides with diisobutylaluminum hydride produced diastereoisomeric -hydroxysulfoxides (IV) in 100% e.e. The reaction of the dianions of I and IV with alkylating reagents or carbonyl compounds lead to the stereoselective carbon-carbon-carbon bond formation. While the intramolecular chelation of a metal cation may play an important role in the reaction of IV, the coordinatio of solvents molecules with a metal cation may be predominat in the dianion of I.In the reactions of these dianions the carbonyl compounds attack the carbanion on the side of a metal cation, whereas the approach of the alkylating reagents was found to be governed by the steric effects regardless of the cation. In the dianion of IV the configurational interconversion of the carbanion took place, and the intramolecular chelation of a metal cation with the adjacent group is assumed to play an important role in the conversion.From I-IV many chiral compounds such as -, -lactones, tetrahydrofurans, and allylic alochols were synthesized in 100% e.e., that is to say, I-IV are very useful chiral building blocks.

手性β-羟基砜（I）、β-羟基砜（II）和β-羟基-硝基化合物（III）的制备均达到100%e. e.通过面包酵母还原相应的酮。用氢化二异丁基铝还原手性-酮基亚砜，得到非对映异构体-羟基亚砜（IV），e. I和IV的二价阴离子与烷基化试剂或羰基化合物的反应导致立体选择性的碳-碳-碳键的形成。虽然金属阳离子的分子内螯合作用可能在IV的反应中发挥重要作用，但溶剂分子与金属阳离子的配位作用可能在I的二价阴离子中占主导地位。在这些二价阴离子的反应中，羰基化合物攻击金属阳离子一侧的碳负离子，而烷基化试剂的方法被发现受空间效应的支配，而与阳离子无关。在Ⅳ的二价阴离子中发生了碳负离子的构型相互转化，金属阳离子与相邻基团的分子内螯合作用在转化过程中起着重要作用。由Ⅰ-Ⅳ合成了许多手性化合物，如-，-内酯，四氢呋喃和烯丙基醇，其e. e.为100%，也就是说，I-IV是非常有用手性结构单元。