Ethyl 1-Methyl-2-methylene-5-oxocyclopentanecarboxylate | 134906-10-8

• 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: Ethyl 1-Methyl-2-methylene-5-oxocyclopentanecarboxylate
• 英文别名: Ethyl 1-methyl-2-methylidene-5-oxocyclopentane-1-carboxylate
• CAS: 134906-10-8
• 化学式: C₁₀H₁₄O₃
• 分子量: 182.219
• InChiKey: IRAQUKVKKLAXBB-UHFFFAOYSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  1.2
• 重原子数：
  13
• 可旋转键数：
  3
• 环数：
  1.0
• sp3杂化的碳原子比例：
  0.6
• 拓扑面积：
  43.4
• 氢给体数：
  0
• 氢受体数：
  3

反应信息

• 作为产物：
  描述：

  ethyl 2-methyl-3-oxohept-6-ynoate 在 重水 、 manganese triacetate 、 碳酸氢钠 作用下， 以 四氢呋喃 、 乙醇 为溶剂， 反应 84.0h， 生成 Ethyl 1-Methyl-2-methylene-5-oxocyclopentanecarboxylate
  参考文献：
  名称：

  Ligand, solvent, and deuterium isotope effects in Mn(III)-based oxidative free-radical cyclizations

  摘要：

  Oxidation of beta-keto ester 1 with Mn(Pic)3 and Cu(OAc)2 affords bicycloalkane 8, not the expected alkene 7, which is formed in high yield with Mn(OAc)3 and Cu(OAc)2. A series of control experiments established that the most likely explanation for this observation is that Mn(PiC)2, but not Mn(OAC)2, reacts with the bicyclic radical 5 more rapidly than Cu(OAc)2 does. These studies also indicate the potential for improved yields from oxidative free-radical cyclization of deuterated substrates. For instance, reaction of beta-keto ester 1-d with 2 equiv of Mn(OAc)3 and no Cu(OAC)2 affords 65% of 8, whereas beta-keto ester 1 provides only 22% of 8 under the same conditions. Large kinetic isotope effects change the nature of the termination step and prevent the formation of acyclic radical 3 by intermolecular hydrogen transfer. Solvent and ligand effects on the oxidation of beta-keto ester 1, malonate 14, and acetylenic beta-keto ester 25 are described.

  DOI：

  10.1021/jo00075a015

文献信息

• Solvent effects on manganese(III)-based oxidative free-radical cyclizations: ethanol and acetic acid
  作者：Barry B. Snider、John E. Merritt、Mark A. Dombroski、Brad O. Buckman

  DOI：10.1021/jo00019a014

  日期：1991.9

  Ethanol complements the typical solvent, acetic acid, for Mn(III)-based oxidative free-radical cyclizations. Cyclization of enol ether 1c to give gibberellic acid intermediate 6c is successful in ethanol, but not in acetic acid. Ethanol acts as a reducing agent for primary radicals, converting 13 and 33 to alkanes 17 and 32. Acetylenes can be used as substrates since the vinyl radicals 24 and 25 are reduced by ethanol to alkenes 26-28. The 1-hydroxyethyl radical obtained from ethanol is oxidized to acetaldehyde by Mn(III). The effect of solvent on the oxidative cyclization of unsaturated beta-keto esters 35 and 48 was examined. A higher percentage of 5-exo product is obtained in ethanol. The primary cyclopentanemethyl radicals 40 and 53 are oxidized mainly to alkenes 43 and 57 in ethanol and mainly to the alcohols 42 and 55 and lactones 41 and 58 in acetic acid.
• Ligand, solvent, and deuterium isotope effects in Mn(III)-based oxidative free-radical cyclizations
  作者：Barry B. Snider、Bridget A. McCarthy

  DOI：10.1021/jo00075a015

  日期：1993.11

  Oxidation of beta-keto ester 1 with Mn(Pic)3 and Cu(OAc)2 affords bicycloalkane 8, not the expected alkene 7, which is formed in high yield with Mn(OAc)3 and Cu(OAc)2. A series of control experiments established that the most likely explanation for this observation is that Mn(PiC)2, but not Mn(OAC)2, reacts with the bicyclic radical 5 more rapidly than Cu(OAc)2 does. These studies also indicate the potential for improved yields from oxidative free-radical cyclization of deuterated substrates. For instance, reaction of beta-keto ester 1-d with 2 equiv of Mn(OAc)3 and no Cu(OAC)2 affords 65% of 8, whereas beta-keto ester 1 provides only 22% of 8 under the same conditions. Large kinetic isotope effects change the nature of the termination step and prevent the formation of acyclic radical 3 by intermolecular hydrogen transfer. Solvent and ligand effects on the oxidation of beta-keto ester 1, malonate 14, and acetylenic beta-keto ester 25 are described.