4-Methyl-5-acetoxy-2-furanone | 131404-94-9

• 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: 4-Methyl-5-acetoxy-2-furanone
• 英文别名: (3-methyl-5-oxo-2H-furan-2-yl) acetate
• CAS: 131404-94-9
• 化学式: C₇H₈O₄
• 分子量: 156.138
• InChiKey: IZDIIXRKALKCHT-UHFFFAOYSA-N

物化性质

• 沸点：
  284.1±40.0 °C(Predicted)
• 密度：
  1.23±0.1 g/cm3(Temp: 20 °C; Press: 760 Torr)(Predicted)

计算性质

• 辛醇/水分配系数(LogP)：
  0.2
• 重原子数：
  11
• 可旋转键数：
  2
• 环数：
  1.0
• sp3杂化的碳原子比例：
  0.43
• 拓扑面积：
  52.6
• 氢给体数：
  0
• 氢受体数：
  4

反应信息

• 作为反应物：
  描述：

  4-Methyl-5-acetoxy-2-furanone 在 palladium on activated charcoal 氢气 、 caesium carbonate 、 lithium hexamethyldisilazane 作用下， 以 四氢呋喃 、 甲醇 、 乙腈 为溶剂， 反应 8.36h， 生成 syn-5-acetoxy-3-acetyl-3-(3-oxobutyl)-4-methyltetrahydrofuran-2-one
  参考文献：
  名称：

  Unexpected Contrasteric Alkylation Leading to a Model for Five-Membered Ring Enolate Alkylation: Short Stereoselective Synthesis of (.+-.)-Acetomycin

  摘要：

  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.

  DOI：

  10.1021/jo00121a025
• 作为产物：
  描述：

  4-甲基-5-羟基呋喃-2-酮 、 乙酸酐 在 吡啶 作用下， 以 二氯甲烷 为溶剂， 生成 4-Methyl-5-acetoxy-2-furanone
  参考文献：
  名称：

  Unexpected Contrasteric Alkylation Leading to a Model for Five-Membered Ring Enolate Alkylation: Short Stereoselective Synthesis of (.+-.)-Acetomycin

  摘要：

  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.

  DOI：

  10.1021/jo00121a025

文献信息

• Lipase catalyzed enantioselective transesterification of 5-acyloxy-2(5H)-furanones
  作者：Hanneke van der Deen、Robert P. Hof、Arjan van Oeveren、Ben L. Feringa、Richard M. Kellogg

  DOI：10.1016/s0040-4039(00)74428-5

  日期：1994.11

  Several lipases catalyse the transesterification of γ-acyloxyfuranones in organic solvents with high enantioselectivities. This method has been used for the kinetic resolution of 5-acetoxy-2(5H)-furanone, 5-acetoxy-4-methyl-2(5H)-furanone and 5-propionyloxy-2(5H)-furanone, in e.e.'s ranging from 68–98%.

  几种脂肪酶催化具有高对映选择性的γ-酰氧基呋喃酮在有机溶剂中的酯交换反应。该方法已用于动力学拆分5-乙酰氧基-2（5H）-呋喃酮，5-乙酰氧基-4-甲基-2（5H）-呋喃酮和5-丙酰氧基-2（5H）-呋喃酮，在ee的范围内从68–98％。
• 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.