dihydro-3α-acetyl-5β-ethoxy-3β,4β-dimethyl-2(3H)-furanone

• 分子结构分类: 有机化合物 - 有机杂环化合物 - 内酯类
• 英文名称: dihydro-3α-acetyl-5β-ethoxy-3β,4β-dimethyl-2(3H)-furanone
• 英文别名: 3-Acetyl-3,4-dimethyl-5-ethoxytetrahydrofuran-2-one；(3R,4S,5R)-3-acetyl-5-ethoxy-3,4-dimethyloxolan-2-one
• 化学式: C₁₀H₁₆O₄
• 分子量: 200.235
• InChiKey: ABNYWYXJKSMNKE-GTNGPMTGSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  1.3
• 重原子数：
  14
• 可旋转键数：
  3
• 环数：
  1.0
• sp3杂化的碳原子比例：
  0.8
• 拓扑面积：
  52.6
• 氢给体数：
  0
• 氢受体数：
  4

反应信息

• 作为产物：
  描述：

  1,1-dimethylethyl 2α-ethoxy-3α-methyl-1α-(1-((1,1-dimethylethyl)dimethylsilyloxy)vinyl)-cyclopropane-1β-carboxylate 在 thallium (I) ethoxide 、 三氟乙酸 作用下， 以 二氯甲烷 为溶剂， 反应 2.33h， 生成 dihydro-3α-acetyl-5β-ethoxy-3β,4β-dimethyl-2(3H)-furanone
  参考文献：
  名称：

  Davies, Huw M. L.; Hu, Baihua, Heterocycles, 1993, vol. 35, # 1, p. 385 - 393

  摘要：

  DOI：

文献信息

• Unexpected Contrasteric Alkylation Leading to a Model for Five-Membered Ring Enolate Alkylation: Short Stereoselective Synthesis of (.+-.)-Acetomycin
  作者：Tara J. Sprules、Jean-Francois Lavallee

  DOI：10.1021/jo00121a025

  日期：1995.8

  It is well established that the alkylation of cyclic enolates 1 bearing an asymmetric center at the beta-position should provide mainly lactones 2 where the electrophile (E(+)) ends up trans to the beta-substituent (R(2)). Our interest in such processes lies in the fact that according to this principle, alkylation of 1a with methyl iodide should provide direct access to (+/-)-acetomycin (2a). However, this reaction unexpectedly afforded the contrasteric alkylation product 3a ((+/-)-3-epi-acetomycin) with high diastereoselectivity. To elucidate this observation, alkylation studies have been carried out on various enolates 1. As normally expected, when R(2) and R(3) are alkyl groups, only product 2 is obtained. On the other hand, when R(3) is an acetoxy or an alkoxy group and methyl iodide is used as electrophile, the contrasteric products 3 are predominant. With sterically more demanding electrophiles, the ''normal'' alkylation products 2 are obtained in moderate to extremely high selectivity. Thus, the use of 1,3-dithienium tetrafluoroborate, a bulky methyl equivalent, allowed us to complete a stereoselective synthesis of(+/-)-acetomycin. These results led to the elaboration of a model for five-membered ring enolate alkylation based on steric and stereoelectronic effects, as well as ring conformations.
• Davies, Huw M. L.; Hu, Baihua, Heterocycles, 1993, vol. 35, # 1, p. 385 - 393
  作者：Davies, Huw M. L.、Hu, Baihua

  DOI：——

  日期：——