合成新生素A,AA和名义新生素K
Sven M Papidocha1, Hendrik H Bulthaupt1, Erick M Carreira1
1Laboratorium für Organische Chemie, ETH Zürich, Vladimir-Prelog-Weg 3, 8093, Zürich, Switzerland.
Angewandte Chemie (International ed. in English)
|September 8, 2023
概括
研究人员首次实现了复杂的卡桑类型的特类新卡萨尔A.A.的总合成. 这一突破利用了一个关键的迪尔斯-阿尔德反应和新的氧化方法来组装和功能化分子.
科学领域:
- 有机化学 有机化学
- 自然产品的合成自然产品的合成
背景情况:
- 卡桑类型的二类物质是具有潜在生物活性的复杂自然产物.
- 尼奥卡萨尔A是该类中高度氧化的一种成员,对合成具有重大挑战.
研究的目的:
- 为了实现首次全合成新凯萨尔A.A.
- 开发复杂的四类生物的高效合成策略.
- 研究相关自然产品之间的结构关系.
主要方法:
- 采用了分子间的迪尔斯-阿尔德反应来构建核心双体框架.
- 用一系列选择性氧化反应来建立所需的氧化模式.
- 开发了一种新介导的氧化,用于后期功能化.
主要成果:
- 首次成功地完成了neocaesalpin A的总合成.
- 合成途径被扩展到制备新西尔AA和新西尔K.
- 证据表明,对neocaesalpin K进行结构修订,建议其与neocaesalpin AA.相同.
结论:
- 新凯萨尔A的总合成表明,这是一种可行的通往这个复杂的迪特尔胺的途径.
- 开发的合成方法适用于相关的自然产品.
- 这项研究澄清了neocaesalpin K和neocaesalpin AA的结构相同性.
相关概念视频
Preparation of 1° Amines: Gabriel Synthesis
3.6K
Direct alkylation is not a suitable method for synthesizing amines because it produces polyalkylated products. Gabriel synthesis is the most preferred method to exclusively make primary amines. The method uses phthalimide, which contains a protected form of nitrogen that participates in alkylation only once to predominantly give primary amines.
Strong bases like NaOH or KOH deprotonate the phthalimide to form the corresponding anion, which acts as a nucleophile. Further, the anion attacks an...
Strong bases like NaOH or KOH deprotonate the phthalimide to form the corresponding anion, which acts as a nucleophile. Further, the anion attacks an...
3.6K
Synthesis of α-Substituted Carbonyl Compounds: The Stork Enamine Reaction
3.4K
α-Substituted ketones or aldehydes can be synthesized from enamines by the Stork enamine reaction, named after its pioneer Gilbert Stork. Enamines are useful synthetic intermediates where the lone pair on nitrogen is in conjugation with the C=C bond. They resemble enolate ions, as the resonance forms of both species have a nucleophilic α carbon.
3.4K
Alkylation of β-Ketoester Enolates: Acetoacetic Ester Synthesis
3.4K
Acetoacetic ester synthesis is a method to obtain ketones from alkyl halides and β-keto esters. The reaction occurs in the presence of an alkoxide base that abstracts the acidic proton of the β-keto esters. The step results in an enolate ion which is doubly stabilized. The enolate then reacts with an alkyl halide via the SN2 process to produce an alkylated ester intermediate with a new C–C bond. The hydrolysis of the intermediate, followed by acidification, results in an...
3.4K
Nomenclature of Aryl and Heterocyclic Amines
2.4K
The simplest aromatic amine is phenylamine, which contains an –NH2 functionality directly attached to an aromatic ring. The name aniline is designated for this skeleton. As shown in Figure 1, the common names of the functionalized anilines involve prefixes ortho-, meta-, and para- to indicate the substitution position. Different functionalized aniline derivatives also have notable trivial names.
2.4K
Ketones with Nonenolizable Aromatic Aldehydes: Claisen–Schmidt Condensation
3.7K
Benzaldehyde, like formaldehyde, lacks an α hydrogen and cannot enolize to form an enolate. Hence, the reaction of benzaldehyde with a ketone in the presence of an aqueous base forms a single crossed product. This reaction is referred to as Claisen–Schmidt condensation.
As the self-condensation of ketones is generally not favored in basic conditions, the self-condensed products do not form in the reaction between ketones and benzaldehyde. The general reaction of Claisen–Schmidt...
As the self-condensation of ketones is generally not favored in basic conditions, the self-condensed products do not form in the reaction between ketones and benzaldehyde. The general reaction of Claisen–Schmidt...
3.7K
Alkylation of β-Diester Enolates: Malonic Ester Synthesis
3.4K
Malonic ester synthesis is a method to obtain α substituted carboxylic acids from ꞵ-diesters such as diethyl malonate and alkyl halides.
3.4K


