(E)-2-ethylidenebicyclo<2.2.2>octan-1-ol | 135107-35-6

• 分子结构分类: 有机化合物 - 有机氧化合物
• 英文名称: (E)-2-ethylidenebicyclo<2.2.2>octan-1-ol
• CAS: 135107-35-6
• 化学式: C₁₀H₁₆O
• 分子量: 152.236
• InChiKey: BPKLQELEQJLTOF-XNWCZRBMSA-N

物化性质

• 沸点：
  225.5±8.0 °C(Predicted)
• 密度：
  1.154±0.06 g/cm3(Predicted)

计算性质

• 辛醇/水分配系数(LogP)：
  2.26
• 重原子数：
  11.0
• 可旋转键数：
  0.0
• 环数：
  3.0
• sp3杂化的碳原子比例：
  0.8
• 拓扑面积：
  20.23
• 氢给体数：
  1.0
• 氢受体数：
  1.0

反应信息

• 作为反应物：
  描述：

  (E)-2-ethylidenebicyclo<2.2.2>octan-1-ol 在 吡啶 、 2,6-二甲基吡啶 作用下， 以 二氯甲烷 为溶剂， 反应 2.5h， 生成 1-Ethoxy-(E)-2-ethylidenebicyclo<2.2.2>octane
  参考文献：
  名称：

  Solvolysis of 2-methylene bicyclic bridgehead derivatives: a model for gradual variation of .pi.-conjugation in carbocations

  摘要：

  The rates of solvolysis in ethanol or 80% ethanol at 25-degrees-C have been determined on 2-methylenebicyclo[2.2.2]oct-1-yl triflate (4a), 2-methylenebicyclo[3.2.1]oct-1-yl triflate (5a), 2-methylenebicyclo[3.2.2]non-1-yl mesylate (6a), 2-methylenebicyclo[3.3.1]non-1-yl mesylate (7a-OMs) and heptafluorobutyrate (7a-OHFB), 1-chloro-2-methylenebicyclo[4.2.2]decane (8a), 2-methylenebicyclo[4.3.1]dec-1-yl trifluoroacetate (9a), and 4-methylene-3-homoadamantyl heptafluorobutyrate (10a) and on their corresponding parent 1-bicycloalkyl and 3-homoadamantyl derivatives 4b-10b containing the respective leaving group. The rate ratios for 4a/4b, 5a/5b, 10a/10b, 6a/6b, 7a/7b, 8a/8b, and 9a/9b are 10(-3.9), 10(-1.9), 10(-1.1), 10(0.8), 10(0.9) (for mesylate), 10(-0.2), and 10(0.7), respectively. A plot of the logarithms of the rate ratios against olefinic strain energies of their corresponding unsubstituted bridgehead olefins shows that the smaller the olefinic strain energy, the greater the rate ratio, providing a methodology to gradually change the conjugative ability of bridgehead carbocations. The enhancement of allylic conjugation with increasing skeletal flexibility has been further verified by the enhanced solvolysis rate of (E)-2-ethylidenebicyclo[3.2.2]non-1-yl mesylate ((E)-6e) relative to 6a by a factor of 259. A similar study on much more rigid (E)-2-ethylidenebicyclo[2.2.2]oct-1-yl triflate ((E)-4e) gave a (E)-4e/4a rate ratio of 6.3. AM1 semiempirical molecular orbital calculations on pertinent 2-methylene and (E)-2-ethylidene bridgehead carbocations and corresponding hydrocarbons (L = hydrogen) also supported the increase in the conjugation with increasing skeletal flexibility. The solvolysis products were solely bridgehead substitution products, no indication for the formation of bridgehead olefin via an S(N)1' mechanism having been obtained.

  DOI：

  10.1021/jo00027a050
• 作为产物：
  描述：

  1-hydroxybicyclo[2.2.2]octan-2-one 在 2,6-二甲基吡啶 、 四丁基氟化铵 、 sodium hydride 作用下， 以 四氢呋喃 、 二氯甲烷 为溶剂， 反应 40.5h， 生成 (E)-2-ethylidenebicyclo<2.2.2>octan-1-ol
  参考文献：
  名称：

  Solvolysis of 2-methylene bicyclic bridgehead derivatives: a model for gradual variation of .pi.-conjugation in carbocations

  摘要：

  The rates of solvolysis in ethanol or 80% ethanol at 25-degrees-C have been determined on 2-methylenebicyclo[2.2.2]oct-1-yl triflate (4a), 2-methylenebicyclo[3.2.1]oct-1-yl triflate (5a), 2-methylenebicyclo[3.2.2]non-1-yl mesylate (6a), 2-methylenebicyclo[3.3.1]non-1-yl mesylate (7a-OMs) and heptafluorobutyrate (7a-OHFB), 1-chloro-2-methylenebicyclo[4.2.2]decane (8a), 2-methylenebicyclo[4.3.1]dec-1-yl trifluoroacetate (9a), and 4-methylene-3-homoadamantyl heptafluorobutyrate (10a) and on their corresponding parent 1-bicycloalkyl and 3-homoadamantyl derivatives 4b-10b containing the respective leaving group. The rate ratios for 4a/4b, 5a/5b, 10a/10b, 6a/6b, 7a/7b, 8a/8b, and 9a/9b are 10(-3.9), 10(-1.9), 10(-1.1), 10(0.8), 10(0.9) (for mesylate), 10(-0.2), and 10(0.7), respectively. A plot of the logarithms of the rate ratios against olefinic strain energies of their corresponding unsubstituted bridgehead olefins shows that the smaller the olefinic strain energy, the greater the rate ratio, providing a methodology to gradually change the conjugative ability of bridgehead carbocations. The enhancement of allylic conjugation with increasing skeletal flexibility has been further verified by the enhanced solvolysis rate of (E)-2-ethylidenebicyclo[3.2.2]non-1-yl mesylate ((E)-6e) relative to 6a by a factor of 259. A similar study on much more rigid (E)-2-ethylidenebicyclo[2.2.2]oct-1-yl triflate ((E)-4e) gave a (E)-4e/4a rate ratio of 6.3. AM1 semiempirical molecular orbital calculations on pertinent 2-methylene and (E)-2-ethylidene bridgehead carbocations and corresponding hydrocarbons (L = hydrogen) also supported the increase in the conjugation with increasing skeletal flexibility. The solvolysis products were solely bridgehead substitution products, no indication for the formation of bridgehead olefin via an S(N)1' mechanism having been obtained.

  DOI：

  10.1021/jo00027a050

文献信息

• Marked leaving group strain in (Z)-2-ethylidenebicyclo[2.2.2]oct-1-yl triflate and its significant relief in (Z)-2-ethylidenebicyclo[3.2.2]non-1-yl mesylate
  作者：Kenichi Takeuchi、Yasushi Ohga、Toshikazu Kitagawa

  DOI：10.1021/jo00017a003

  日期：1991.8

  The rate of ethanolysis at 25-degrees-C of (Z)-2-ethylidenebicyclo[2.2.2]oct-1-yl triflate [(Z)-3] is 217 times faster than that of its E isomer, whereas more flexible (Z)-2-ethylidenebicyclo[3.2.2]non-1-yl mesylate solvolyzes 3.4 times slower than its E isomer, indicating marked leaving-group strain in the ground state of (Z)-3, which is supported by MM2 calculations.