总合成的 (±) - 环黄和 (±) -5-epi-环黄
Filip R Petronijevic1, Peter Wipf
1Department of Chemistry and Center for Chemical Methodologies and Library Development, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, USA.
Journal of the American Chemical Society
|April 27, 2011
概括
研究人员开发了新的合成途径,用于印类类化合物环黄及其C(5) -epimer. 关键步骤涉及使用迪尔斯-阿尔德反应和独特的环[c]印构建块形成的快速异环核构造.
科学领域:
- 有机化学 有机化学
- 合成化学 合成化学
- 自然产品的合成自然产品的合成
背景情况:
- 印度醇类化合物,如环类,是具有复杂结构的重要自然产品类.
- 有效和立体选择性的合成路径对于获取这些化合物及其类似物进行进一步研究至关重要.
研究的目的:
- 设计新型合成策略,用于构建循环氨酸及其非自然C(5) -epimer.
- 探索迪尔斯-阿尔德反应在构建循环的核心异环框架中的实用性.
主要方法:
- 采用了两个迪尔斯-阿尔德反应,用于快速组装异环芯片.
- 采用了后期的分子内迪尔斯-阿尔德 furan 循环添加剂来进行印醇取消.
- 纳入了一个立体选择性的分子内 [4 + 2] 循环添加与甲基烯cyclopropane dienophile 形成 cyclopropa[c]indoline 部分.
主要成果:
- 成功建立了新型合成路径,以获得环洛克拉及其C(5) -epimer.
- 证明了Diels-Alder循环添加在构建关键结构元素中的效率.
- 通过刻板选择生成了特征性的环[c]印素构建块.
结论:
- 开发的合成途径提供了有效的循环氨酸及其表皮胺的获取.
- 这项研究强调了Diels-Alder反应在复杂的天然产品合成中的力量.
- 该方法提供了一个有价值的平台,用于访问相关的醇类结构.
相关概念视频
Cycloaddition Reactions: Overview
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Stereoisomerism of Cyclic Compounds
In this lesson, we delve into the role of ring conformation and its stability, which determines the spatial arrangement and, consequently, the molecular symmetry and stereoisomerism of cyclic compounds. 1,2-Dimethylcyclohexane is used as a case study to evaluate the possible number of stereoisomers. Here, given the multiple (n = 2) chiral centers, there are 2n = 4 possible configurations that lack a plane of symmetry, as the ring skeleton exists in a non-planar chair conformation. In addition,...
Prochirality
The concept of prochirality leads to the nomenclature of the individual faces of a molecule and plays a crucial role in the enantioselective reaction. It is a concept where two or more achiral molecules react to produce chiral products. A typical process is the reaction of an achiral ketone to generate a chiral alcohol. Here, the achiral reactant reacts with an achiral reducing agent, sodium borohydride, to generate an equimolar mixture of the chiral enantiomers of the product. For example, an...
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Depending upon the different spatial orientation of the substituents, the disubstituted cycloalkanes exhibit two types of stereoisomers. The cis isomers have the substituents on the same side of the ring, whereas the trans isomers have the substituents on the opposite sides. These stereoisomers exhibit different physical properties and cannot be interconverted without breaking the carbon-carbon bonds.
In cyclohexane, the substituents can occupy different positions generating distinct isomers.
In cyclohexane, the substituents can occupy different positions generating distinct isomers.
[3,3] Sigmatropic Rearrangement of Allyl Vinyl Ethers: Claisen Rearrangement
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Cyclohexenones via Michael Addition and Aldol Condensation: The Robinson Annulation
Robinson annulation is a base-catalyzed reaction for the synthesis of 2-cyclohexenone derivatives from 1,3-dicarbonyl donors (such as cyclic diketones, β-ketoesters, or β-diketones) and α,β-unsaturated carbonyl acceptors. Named after Sir Robert Robinson, who discovered it, this reaction yields a six-membered ring with three new C–C bonds (two σ bonds and one π bond).


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