(E)-4-(2-methylprop-1-enyl)-5-(2-methylpropylidene)cyclopent-1-enyl acetate | 1221493-03-3

• 分子结构分类: 有机化合物 - 有机酸及其衍生物 - 羧酸及其衍生物
• 英文名称: (E)-4-(2-methylprop-1-enyl)-5-(2-methylpropylidene)cyclopent-1-enyl acetate
• 英文别名: [(5E)-4-(2-methylprop-1-enyl)-5-(2-methylpropylidene)cyclopenten-1-yl] acetate
• CAS: 1221493-03-3
• 化学式: C₁₅H₂₂O₂
• 分子量: 234.338
• InChiKey: AHAUICPTOUQQHH-NTEUORMPSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  3.7
• 重原子数：
  17
• 可旋转键数：
  4
• 环数：
  1.0
• sp3杂化的碳原子比例：
  0.53
• 拓扑面积：
  26.3
• 氢给体数：
  0
• 氢受体数：
  2

反应信息

• 作为反应物：
  描述：

  (E)-4-(2-methylprop-1-enyl)-5-(2-methylpropylidene)cyclopent-1-enyl acetate 在 potassium carbonate 作用下， 以 甲醇 、 二氯甲烷 为溶剂， 反应 1.0h， 生成 (E)-3-(2-methylprop-1-enyl)-2-(2-methylpropylidene)cyclopentanone
  参考文献：
  名称：

  Mechanistic Insights in Gold-Stabilized Nonclassical Carbocations: Gold-Catalyzed Rearrangement of 3-Cyclopropyl Propargylic Acetates

  摘要：

  The reaction of 3-cyclopropyl propargylic carboxylates with Au(I) and Au(III) catalysts affords selectively 5-(E)-alkylidenecyclopentenyl acetates via [3,3]-sigmatropic rearrangement of the carboxylic moiety followed by cyclopropyl ring opening and cyclization. DFT calculations have been performed, supporting a two-step no-intermediate mechanism along the cyclization coordinate. The stereoselective formation of the exocyclic alkenes is kinetically controlled in the first of these events. Although stereospecific in nature through a gold-stabilized nonclassical carbocation, the chirality transfer in these cyclopentannulations is not complete. Computational and experimental evidence is provided for a Au-promoted cyclopropyl ring opening/epimerization/ring closure in both cis- and trans-cyclopropyl settings, which competes with the cyclization event, thus eroding the stereochemical information transfer. When tertiary acetates were used, products of both 1,2- and 1,3-acyloxy migration processes could be isolated, supporting the competitive coexistence of these two pathways along the reaction profile, as suggested also by DFT calculations.

  DOI：

  10.1021/ja909013j
• 作为产物：
  描述：

  4-methyl-1-(2-(2-methylprop-1-enyl)cyclopropyl)pent-1-yn-3-yl acetate 在 (IPr)Au(NTf₂) 作用下， 以 二氯甲烷 为溶剂， 反应 0.5h， 生成 (E)-4-(2-methylprop-1-enyl)-5-(2-methylpropylidene)cyclopent-1-enyl acetate 、 (Z)-4-(2-methylprop-1-enyl)-5-(2-methylpropylidene)cyclopent-1-enyl acetate
  参考文献：
  名称：

  Mechanistic Insights in Gold-Stabilized Nonclassical Carbocations: Gold-Catalyzed Rearrangement of 3-Cyclopropyl Propargylic Acetates

  摘要：

  The reaction of 3-cyclopropyl propargylic carboxylates with Au(I) and Au(III) catalysts affords selectively 5-(E)-alkylidenecyclopentenyl acetates via [3,3]-sigmatropic rearrangement of the carboxylic moiety followed by cyclopropyl ring opening and cyclization. DFT calculations have been performed, supporting a two-step no-intermediate mechanism along the cyclization coordinate. The stereoselective formation of the exocyclic alkenes is kinetically controlled in the first of these events. Although stereospecific in nature through a gold-stabilized nonclassical carbocation, the chirality transfer in these cyclopentannulations is not complete. Computational and experimental evidence is provided for a Au-promoted cyclopropyl ring opening/epimerization/ring closure in both cis- and trans-cyclopropyl settings, which competes with the cyclization event, thus eroding the stereochemical information transfer. When tertiary acetates were used, products of both 1,2- and 1,3-acyloxy migration processes could be isolated, supporting the competitive coexistence of these two pathways along the reaction profile, as suggested also by DFT calculations.

  DOI：

  10.1021/ja909013j