Asymmetric Synthesis using Enantiomerically Defined alpha-Oxystannanes

使用对映体定义的 α-氧基锡烷进行不对称合成

• 批准号: 05453136
• 负责人: NAKAI Takeshi
• 金额: $ 3.71万
• 依托单位: Tokyo Institute of Technology
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (B)
• 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
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-05453136/
• 关键词: Enantiomerically defined alpha-oxystannanes; Asymmetric synthesis; Carboanion reaction; Asymmetric [2,3] -Wittig rearrangement; Asymmetric [1,2] -Wittig rearrangement; Asymmetric carbolithiative cyclization

The purpose of this work is to develop the new method for asymmetric synthesis using enantiomerically defined alpha-oxystannanes. A summary of the research results is as follow :(1) A new practical method for asymmetric synthesis of alpha-hydroxystannanesThe TiCl_4-promoted reaction of (4S,6S) - (4,6-dimethyl-1,3-dioxan-2-yl) tributylstannane with Grignard reagents is shown to sfford, after oxidation followed by base treatment, the (S) -alpha-hydroxystannanes in >95-20% ee.(2) Asymmetric [2,3] -Wittig rearrangementThe [2,3] -Wittig rearrangement of enantiomerically-defined alpha- (allyloxy) stannanes, prepared from (S) -1-tributylstannyl-1-propanol, with butyllithium is shown to proceed with essentially complete inversion of configuration at the Li-bearing migrating terminus.(3) Asymmetric [1,2] -Wittig rearrangementThe [1,2] -Wittig rearrangements of enantio-defined alpha-benzyloxypropyllithium and its (R) -alpha-methylbenzyloxy analogs, generated from the enantio-enriched stannanes via Sn/Li exchange, are shown to proceed predominantly with inversion of configuration at the Li-bearing terminus and retention of configuration at the migrating center, and exhibit a significant level of mutual enantiomer recognition in the radical recombination process.(4) Asymmetric carbolithiative cyclizationThe carbolithiative cyclization of enantiomerically-defined alpha-(homoallyloxy)stannane, with butyllithium is shown to proceed with complete retention of configuration at the Li-bearing center.

本工作的目的是发展一种利用对映体确定的α-氧锡烷进行不对称合成的新方法。（1）α-羟基锡烷不对称合成的新方法在TiCl_4促进下，（4S，6S）-（4，6-二甲基-1，3-二氧六环-2-基）三丁基锡烷与格氏试剂反应，经氧化、碱处理后，产物ee>95-20%。(2)不对称[2，3]-Wittig重排由（S）-1-三丁基锡烷基-1-丙醇制备的对映体定义的α-（烯丙氧基）锡烷与丁基锂的[2，3] -Wittig重排显示在含锂迁移末端进行基本上完全的构型反转。(3)不对称[1，2]-Wittig重排反应由对映体富集的锡烷通过Sn/Li交换生成的对映体定义的α-苄氧基丙基锂及其（R）-α-甲基苄氧基类似物的[1，2] -Wittig重排反应主要在含锂末端进行构型反转，并在迁移中心保留构型，并且在自由基重组过程中表现出显著水平的相互对映体识别。(4)不对称碳锂化环化对映体定义的α-（高烯丙氧基）锡烷与丁基锂的碳锂化环化反应显示在含锂中心完全保留构型的情况下进行。

项目成果

Katsuhiko Tomooka: "A practical synthetic method for enantio-enriched alpha-hydroxystannanes" Tetrahedron Lett. 35. 1913-1916 (1994)

Katsuhiko Tomooka：“一种对映体富集的 α-羟基锡烷的实用合成方法”Tetrahedron Lett。

中井 武: "[1,2]-Wittig rearrangement of enantio-defined α-alkoxyalkyllithiums:Structural requirement and steric course at the Li-bearing terminus." Tetrahedron. 50. 5927-5932 (1994)

Takeshi Nakai：“对映体定义的 α-烷氧基烷基锂的 [1,2]-Wittig 重排：含锂末端的结构要求和空间过程。” 50. 5927-5932 (1994)

中井武: "[2,3]-Wittig rearrangement using Glucose as a chiral auxiliary:Asymmetric transmission from the anomeric center" Synlett. (印刷中). (1995)

Takeshi Nakai：“使用葡萄糖作为手性助剂的 [2,3]-Wittig 重排：异头中心的不对称传输”Synlett（出版中）。

Takeshi Nakai: "Enantioselective [2,3] Wittig Rearrangement Involving a Chiral Boron Enolate Terminus" Tetrahedron Lett. 35. 5019-5022 (1994)

Takeshi Nakai：“涉及手性硼烯醇末端的对映选择性 [2,3] Wittig 重排”四面体莱特。

中井武: "[2,3]-Wittig Rearrangement of Enantiomerically-Defined α-(Allyloxy)stannanes:Solid Evidence for Inversion of Configuration at the Lithium-BearingMigrating Terminus" Tetrahedron Letters. 33. 5795-5798 (1992)

Takeshi Nakai：“对映体定义的 α-(烯丙氧基)锡烷的 [2,3]-Wittig 重排：含锂迁移末端构型反转的可靠证据”四面体快报 33。 5795-5798 (1992)