不对称的C-糖的区域选择性合成,使用连接物作为一次性连接剂
David E Kaelin1, Steven M Sparks, Hilary R Plake
1Department of Chemistry and Biochemistry, University of Texas, Austin, TX 78712-0615, USA.
Journal of the American Chemical Society
|October 23, 2003
概括
使区域选择性迪尔斯-阿尔德反应成为可能,这是合成不对称的C-糖化物的一个关键步骤. 这种方法通过分子内循环添加和随后的转化有效地产生单同位素甘酸盐.
科学领域:
- 有机化学 有机化学
- 合成化学 合成化学
- 葡萄糖科学 (Glycoscience) 是一种科学.
背景情况:
- 在药物化学和材料科学中,C-aryl糖化物很重要.
- 合成具有定义区域化学的非对称C-基糖化物仍然具有挑战性.
- 现有的方法往往缺乏对立体化学和区域选择性的控制.
研究的目的:
- 开发一种新的战略,用于非对称的C-aryl糖化物区域选择性合成.
- 为了利用连接器来控制素和甘酸之间的迪尔斯-阿尔德反应.
- 建立一条通往三大类C-糖化物多功能通道.
主要方法:
- 制备循环添加前体,通过O-基化醇与furylsilane衍生物.
- 局部产生的的分子内迪尔斯-阿尔德反应,由连接器指导.
- 化物诱导的带去除和酸催化环开放产生C-糖化物.
主要成果:
- 成功合成具有高区域选择性的非对称C-基糖化物.
- 通过分子内迪尔斯-阿尔德反应形成桥梁循环载荷管道.
- 在去除和开环后,以单个异构体获得所需的C-基化物.
结论:
- 连接器在-循环添加剂中提供有效的区域化学控制.
- 开发的方法提供了一个多功能和高效的途径,复杂的C-aryl糖化物.
- 这一策略有助于获取多种不对称的C-烯糖化物结构.
相关概念视频
Structural Isomerism
Isomerism in Complexes
Isomers are different chemical species that have the same chemical formula. Structural isomerism of coordination compounds can be divided into two subcategories, the linkage isomers and coordination-sphere isomers.
Linkage isomers occur when the coordination compound contains a ligand that can bind to the transition metal center through two different atoms. For example, the CN− ligand can bind through the carbon atom or through the nitrogen atom. Similarly, SCN− can be...
Isomers are different chemical species that have the same chemical formula. Structural isomerism of coordination compounds can be divided into two subcategories, the linkage isomers and coordination-sphere isomers.
Linkage isomers occur when the coordination compound contains a ligand that can bind to the transition metal center through two different atoms. For example, the CN− ligand can bind through the carbon atom or through the nitrogen atom. Similarly, SCN− can be...
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[3,3] Sigmatropic Rearrangement of 1,5-Dienes: Cope Rearrangement
The Cope rearrangement is classified as a [3,3] sigmatropic shift in 1,5-dienes, leading to a more stable, isomeric 1,5-diene. The reaction involves a concerted movement of six electrons, four from two π bonds and two from a σ bond, via an energetically favorable chair-like transition state.
C–C Bond Formation: Aldol Condensation Overview
Aldol condensation is an important route in synthetic organic chemistry used to generate a new carbon–carbon bond under basic or acidic conditions. The aldol condensation reaction presented in Figure 1 constitutes an aldol addition reaction followed by the dehydration process.
C–C Bond Cleavage: Retro-Aldol Reaction
The reverse of the aldol addition reaction is called the retro-aldol reaction. Here, the carbon–carbon bond in the aldol product is cleaved under acidic or basic conditions to form two molecules of carbonyl compounds. The mechanism of the reaction consists of three steps.
In the first step, as depicted in Figure 1, the base deprotonates the β-hydroxy ketone at the hydroxyl group to form an alkoxide ion.
In the first step, as depicted in Figure 1, the base deprotonates the β-hydroxy ketone at the hydroxyl group to form an alkoxide ion.


