Development of new synthetic reactions based on the reactions of α, β-epoxysilanes and nucleophiles

基于α，β-环氧硅烷和亲核试剂反应的新合成反应的开发

基本信息

批准号：
10671986
负责人：
TAKEDA Kei
金额：
$ 2.11万
依托单位：
Hiroshima University (2000)Toyama Medical and Pharmaceutical University (1998-1999)
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1998
资助国家：
日本
起止时间：
1998 至 2000
项目状态：
已结题

项目摘要

The objective of this study has been to develop new synthetic reactions based on the reaction of α, β-epoxysilanes with a nucleophile.1. Stereospecific Construction of Eight-Membered CarbocyclesWhen γ-acryloylacylsilane was treated with vinyllithium, a cyclooctenone derivative was obtained as a single diastereomer via an anionic oxy-Cope rearrangement of 1, 2-divinylcyclobutanediol intermediate generated by way of Brook rearrangement of the 1, 2-adduct of the vinyllithium. Furthermore, we found a more versatile methodology for the synthesis of the carbocycles, which involves the reaction of γ-vinyl-γ-silyl-γ-lactones, prepared from β-methoxycarbonyacylsilane with vinyllithium, with vinyllithium.2. Reaction of O-silyl Cyanohydrin derivatives of α, β-Epoxy-β-silylpropanal with Bases in the Presence of Alkylating AgentsReaction of O-silyl cyanohydrin derivatives of α, β-Epoxy-β-silylpropanal with a strong base such as LDA, NHMDS in the presence of alkyl iodide afforded 2-alkylated derivatives of 2, 4-bis (siloxy)-3-butenenitrile as a single isomer in excellent yields. The fact that no O-alkylated and 4-alkylated products were obtained suggests that the tandem processes involving proton abstraction/epoxide ring opening/Brook rearrangement/allylic rearrangement/alkylation would occur in a concerted manner. The use of readily available optically active epoxides in the reaction seems very promising for construction of quaternary chiral centers and will be the subject of further studies.

本研究的目的是基于α,β-环氧硅烷与亲核试剂的反应开发新的合成反应。 1．八元碳环的立体定向构建当γ-丙烯酰基硅烷用乙烯基锂处理时，得到环辛烯酮衍生物。通过 1, 2-二乙烯基环丁二醇中间体的阴离子 oxy-Cope 重排生成单一非对映体此外，我们发现了一种更通用的碳环合成方法，其中涉及由β制备的γ-乙烯基-γ-甲硅烷基-γ-内酯的反应。 -甲氧基羰基硅烷与乙烯基锂，与α，β-环氧-β-甲硅烷基丙醛的O-甲硅烷基氰醇衍生物与碱的反应。烷基化剂存在下α,β-环氧-β-甲硅烷基丙醛的O-甲硅烷基氰醇衍生物与强碱如LDA、NHMDS在烷基碘存在下反应得到2,4-双(甲硅烷氧基)的2-烷基化衍生物)-3-丁烯腈作为单一异构体，具有优异的产率，并且没有 O-烷基化。获得的4-烷基化产物表明，涉及质子夺取/环氧化物开环/布鲁克重排/烯丙基重排/烷基化的串联过程将以协调的方式发生，在反应中使用容易获得的光学活性环氧化物对于构建4-烷基化产物似乎非常有前景。四级手性中心，将成为进一步研究的主题。