ethyl (3S,1'R,2'S)-3-(2'-hydroxy-1'-methylpropyloxy)-2,2-dimethyl-5-phenyl-4-pentynoate

• 分子结构分类: 有机化合物 - 脂质和类脂质分子 - 脂肪酰基
• 英文名称: ethyl (3S,1'R,2'S)-3-(2'-hydroxy-1'-methylpropyloxy)-2,2-dimethyl-5-phenyl-4-pentynoate
• 英文别名: ethyl (3S)-3-[(2R,3S)-3-hydroxybutan-2-yl]oxy-2,2-dimethyl-5-phenylpent-4-ynoate
• 化学式: C₁₉H₂₆O₄
• 分子量: 318.413
• InChiKey: AZOKWNAXCMHTLG-UXLLHSPISA-N

计算性质

• 辛醇/水分配系数(LogP)：
  3.3
• 重原子数：
  23
• 可旋转键数：
  8
• 环数：
  1.0
• sp3杂化的碳原子比例：
  0.53
• 拓扑面积：
  55.8
• 氢给体数：
  1
• 氢受体数：
  4

反应信息

• 作为产物：
  描述：

  苯丙炔醛缩二乙醛 在 (S)-oxazaborolinine 、 对甲苯磺酸 作用下， 以 二氯甲烷 、 甲苯 为溶剂， 反应 24.0h， 生成 ethyl (3S,1'R,2'S)-3-(2'-hydroxy-1'-methylpropyloxy)-2,2-dimethyl-5-phenyl-4-pentynoate
  参考文献：
  名称：

  Mechanism of Chiral Lewis Acid Mediated Enantiotopic Group-Selective Ring Cleavage of Cyclic Acetals Derived from meso-1,2-Diols

  摘要：

  Diastereoselectivity and enantioselectivity of chiral oxazaborolidine-mediated ring-cleavage reactions of meso-2,4,5-trisubstituted 1,3-dioxolane acetals with a trimethylsilyl ketene acetal were investigated in detail and discussed in terms of a mechanism involving a contact ion pair as a product-forming intermediate. Both diastereomeric 2-phenyl derivatives syn- and anti-11a gave the same ring-cleavage product 13a. However, the reaction of 2-phenylethynyl derivatives syn- and anti-11b proceeded almost stereospecifically, giving rise to 13b and 14b, respectively. In all of the reactions, isomerization of diastereomeric acetals was not observed. On the basis of these results, it was deduced that the dissociation of a: Lewis acid-acetal complex is the rate-determining step, and the resulting ion pair intermediate undergoes either isomerization to a diastereomeric acetal or attack by a nucleophile depending on the structure of the acetal. The possible enantioselection at the product-forming step was ruled out. It was proposed that the observed enantioselectivity is determined by enantiodifferentiating coordination of the acetal oxygen atom by the chiral Lewis acid.

  DOI：

  10.1021/jo991071n

文献信息

• Chiral Oxazaborolidinone-Mediated Enantioselective Ring-Cleavage Reaction of a Mixture of Diastereomeric 1,3-Dioxolane Acetals: Application to Asymmetric Desymmetrization of <i>meso</i>-1,2-Diols
  作者：Toshiro Harada、Hideki Yamanaka、Akira Oku

  DOI：10.1055/s-2001-9730

  日期：——

  Ring-cleavage reaction of a mixture of diastereomeric dioxolane acetals syn- and anti-1b-e proceeds in an enantiodifferentiating manner in the presence of chiral Lewis acid 2. The reaction is utilized as a key step in asymmetric desymmetrization of meso-1,2-diols.

  在手性路易斯酸 2 存在下，非对映体二氧戊环缩醛顺式和反式 1b-e 混合物的开环反应以对映分化方式进行。该反应被用作内消旋 1,2 不对称去对称化的关键步骤-二醇。