(2Z,4E)-3,7-Dimethyl-2,4-octadienoic acid ethyl ester | 121950-13-8

• 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: (2Z,4E)-3,7-Dimethyl-2,4-octadienoic acid ethyl ester
• 英文别名: ethyl 3,7-dimethyl-2,4-octadienoate；ethyl (2Z,4E)-3,7-dimethylocta-2,4-dienoate
• CAS: 121950-13-8
• 化学式: C₁₂H₂₀O₂
• 分子量: 196.29
• InChiKey: MQXSHODTFHTCBI-RVNZKKONSA-N

物化性质

• 沸点：
  257.5±9.0 °C(Predicted)
• 密度：
  0.902±0.06 g/cm3(Predicted)

计算性质

• 辛醇/水分配系数(LogP)：
  3.1
• 重原子数：
  14.0
• 可旋转键数：
  5.0
• 环数：
  0.0
• sp3杂化的碳原子比例：
  0.58
• 拓扑面积：
  26.3
• 氢给体数：
  0.0
• 氢受体数：
  2.0

反应信息

• 作为产物：
  描述：

  ethyl 4-bromo-3-methylcrotonate 在 氢氧化钾 、 18-冠醚-6 作用下， 以 苯 为溶剂， 反应 9.0h， 生成 (2Z,4E)-3,7-Dimethyl-2,4-octadienoic acid ethyl ester
  参考文献：
  名称：

  Stereochemistry of Horner-Emmons reaction between 3-functionally substituted 2-methyl-2-propenylphosphonates and aliphatic aldehydes. 3. Effect of the acyclic and dioxaalkylene substituents at the phosphorus atom

  摘要：

  The steric selectivity of the Horner-Emmons reaction between isovaleraldehyde and 3-carboethoxy-2-methyl-2-propenylphosphonates depends on the structure of the alkoxy substituents at the phosphorus atom. The use of five- and six-membered cyclic phosphonates permits us to prepare esters of 3,7-dimethyl-2, 4-octadienoic acids with the predominance of the 2Z,4E isomer.

  DOI：

  10.1007/bf00962398

文献信息

• Stereochemistry of the Horner-Emmons reaction between 3-functionally substituted 2-methyl-2-propenylphosphonates and aliphatic aldehydes. 4. Effect of the nature of the aliphatic aldehyde and concentration of the starting reagents
  作者：G. V. Kryshtal'、�. P. Serebryakov、L. M. Suslova、L. A. Yanovskaya

  DOI：10.1007/bf00962399

  日期：1990.6

  The double bond formed in the Horner-Emmons reaction has only E configuration independently of the structure of the saturated linear, alpha-branched, and beta-branched aliphatic aldehydes upon their reaction with the diethyl ester of 3-ethoxycarbonyl-2-methyl-2-propenylphosphonic acid, while the ratio of the 2E, 4E and 2Z,4E isomers in the reaction product varies only from 58:42 to 62:38. An increase in the aldehyde concentration leads to an increase in the fraction of the 2Z,4E isomer in the ethyl ester of 2E/Z,4E-3,7-dimethyl-2,4-octadienoic acid formed.
• Stereochemistry of the Horner-Emmons reaction of 3-functionalized 2-methyl-2-propenylphosphonates with aliphatic aldehydes. 1. Effect of size of the alkoxy group attached to the phosphorus atom
  作者：G. V. Kryshtal'、�. P. Serebryakov、L. M. Suslova、L. A. Yanovskaya

  DOI：10.1007/bf00953422

  日期：1988.10
• Stereochemistry of the Horner-Emmons reaction of 3-functionalized 2-methyl-2-propenylphosphonates with aliphatic aldehydes 5. Effects of base anion, temperature, solvent, and addition of a crown ether
  作者：G. V. Kryshtal'、�. P. Serebryakov、L. M. Suslova、L. A. Yanovskaya

  DOI：10.1007/bf00958842

  日期：1990.11

  Taking the reaction of diethyl 3-ethoxycarbonyl-2-methyl-2-propenylphosphonate with 3-methylbutanal as an example, it has been shown that the composition of the equilibrium mixture of the E- and Z-isomers of the starting phosphonate formed in the presence of bases is independent of the base anion (KOH or K2CO3) and the solvent (benzene or DMSO). In the mixture of 2E,4E- and 2Z,4E-isomers of ethyl 3,7-dimethyl-2,4-octadienoate formed in this reaction, the proportion of the 2E,4E-ester falls as the temperature is reduced from +40 to -40-degrees-C; the proportion of the 2E,4E-ester in the heterophase system base/aprotic solvent increases with increasing polarity; and in the presence of 10 mole % of 18-crown-6 ether the proportion of the 2E,4E-isomer is increased, being greater than 50% in all solvents. These findings indicate that the stereochemical outcome of the reaction depends on the balance between the phase systems and the chemical equilibria, including the formation, dissociation, and reactions of the intermediate products.