醛醇冷凝反應

什麼是縮合反應？什麼是縮合反應？

醛醇縮合反應 醛醇縮合反應 是由 Charles Wurtz 提出的有機反應，他於 1872 年首次從乙醛染料中製備出β-羥基醛。¹ 在醛醇縮合反應中，烯酸根離子與羰基化合物在酸/鹼催化劑的存在下反應，形成β-羥基醛或β-羥基酮，然後脫水得到共轭烯酮。這是一個有用的碳-碳鍵形成反應。醛缩合反应的基本步骤如下：

1. 醛 （醛醛 + 醇）  - 在 NaOH 或 KOH 的存在下，醛（或酮）烯酸鹽與另一分子的醛（或酮）反應，生成 β-羥基醛（或酮）。

2. 脫水/氫化反應 -涉及從β-氫氧基醛（或酮）中去除一個水分子，形成α,β-不飽和醛或α,β-不飽和酮。

注意事項

請參閱安全資料表，以瞭解有關危害和安全處理實務的資訊。

應用

醛缩合反應可用於下列合成：

• 脂肪酸的酶法合成。²
• 表噻吩酮 B 的高簡潔總合成。³
• (E)-6-(2,2,3-三甲基-環戊-3-烯基)-己-4-烯-3-酮的制備。⁴
• 高聚物聚戊二醛的合成。⁵
• (±)-麻黃素的全選擇性合成。⁶
• 多種大環內酯類和離子抗生素（天然產品）的合成。⁷
• 全合成 distomadines A 和 B，兩種結構獨特的四環喹諾酮類化合物。⁸

近期研究與趨勢

• 利用水溶性鈣[n]烷作為反相轉移催化劑，進行活化甲基和亞甲基化合物的醛醇型縮合反應和邁克爾加成反應。⁹
• 在 SBA-15 介孔分子支持物上使用了含銫離子催化劑，用於乙酸甲酯與甲醛的醛醇縮合法。¹⁰
• 環己酮與 p硝基苯甲醛在水中的有機催化不對稱醛化反應已被報導。¹¹
• 據報導，一鍋銅催化的醚化/醛醇 縮合級聯反應產生二苯並氧西平內酰胺。¹²
• 通過烷基化、區域選擇性碘化、醛醇缩合、鈴木偶合和[1,3]-sigmatropic重排合成一系列二苯乙烯基化和二根苯乙烯基化查爾酮類似物。¹³
• 在甲醇溶劑中，當 KOH 存在時，苊醌與苯乙酮進行 Michael 加成和 aldol 縮合的多米諾序列會形成不同的 2:2 加合物。¹⁴
• 使用功能化的 MCM-41 進行了 4-isopropylbenzaldehyde 與丙醛的醛醇縮合作用。

參考資料

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