(±) -ビサボスクアルAの総合成
Christopher W am Ende1, Zhou Zhou, Kathlyn A Parker
1Department of Chemistry, Stony Brook University, Stony Brook, New York 11794, USA.
Journal of the American Chemical Society
|December 28, 2012
まとめ
研究者は14段階の経路を使用して,新しいスクワレン合成酵素阻害剤であるビサボスクワールAを合成しました. キータンデムラジカルサイクライゼーションは,高ステレオコントロールで複雑なテトラサイクリックコアを効率的に構築しました.
科学分野:
- 有機化学 オーガニック・ケミストリー
- 薬用化学 薬用化学について
- 合成化学 合成化学とは
背景:
- スクアレン合成酵素は,コレステロール生物合成の重要な酵素です.
- スクアレン合成酵素の阻害剤は,高コレステロール血症の潜在的な治療薬です.
- ビサボスクワールAは,複雑な四環構造を持つ新しい阻害剤です.
研究 の 目的:
- 新型スクワレン合成酵素阻害剤ビサボスクワールAの合成経路を開発する.
- テトラサイクルのコア構造の効率的でステレオ選択的な合成を確立する.
主な方法:
- 商業的に利用可能な原材料から14段階の合成.
- 双重収束した合成戦略.
- テトラサイクリックコアを構成するための重要なタンデム5 - エクソ, 6 - エクソラジカルサイクリング.
- 地域選択的脱酸素化とステレオ選択的有機金属添加反応.
主要な成果:
- ビサボスクバルAの合成が成功しました.
- 完全に機能したテトラサイクルコアの効率的な組み立て.
- 3つのステレオジェニックセンターを導入し,高度な制御を行います.
- 地域選択とステレオ選択の変換の実証.
結論:
- ビサボスクワールAへの有効な合成経路が確立されています.
- キーラジカルサイクライゼーションは,複雑なポリサイクリックシステムを構築するための効果的な方法です.
- 合成は,機能的グループ操作とステレオセンター導入のための効率的な方法を強調しています.
関連する概念動画
02:23SN2 Reaction: Stereochemistry
In an SN2 reaction, the nucleophilic attack on the substrate and departure of the leaving group occurs simultaneously through a transition state. As the nucleophile approaches the substrate from the back-side, the configuration of the substrate carbon changes from tetrahedral to trigonal bipyramidal and then back to tetrahedral, leading to an inversion in the configuration of the product.
If the substrate is an achiral molecule at the α-carbon, the inversion of configuration is not observed.
If the substrate is an achiral molecule at the α-carbon, the inversion of configuration is not observed.
01:22Electrophilic Aromatic Substitution: Sulfonation of Benzene
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01:30Nucleophilic Aromatic Substitution: Addition–Elimination (SNAr)
Nucleophilic substitution in aromatic compounds is feasible in substrates bearing strong electron-withdrawing substituents positioned ortho or para to the leaving group. The reaction proceeds via two steps: the addition of the nucleophile and the elimination of the leaving group.
The reaction begins with an attack of the nucleophile on the carbon that holds the leaving group. This results in the delocalization of the π electrons over the ring carbons. The resonance interaction between the...
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01:14Alkylation of β-Diester Enolates: Malonic Ester Synthesis
Malonic ester synthesis is a method to obtain α substituted carboxylic acids from ꞵ-diesters such as diethyl malonate and alkyl halides.
01:11Nucleophilic Aromatic Substitution: Elimination–Addition
Simple aryl halides do not react with nucleophiles. However, nucleophilic aromatic substitutions can be forced under certain conditions, such as high temperatures or strong bases. The mechanism of substitution under such conditions involves the highly unstable and reactive benzyne intermediate. Benzyne contains equivalent carbon centers at both ends of the triple bond, each of which is equally susceptible to nucleophilic attack. This 50–50 distribution of products is confirmed through isotopic...
01:07Alkylation of β-Ketoester Enolates: Acetoacetic Ester Synthesis
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