4,5-diethoxy-2-methyl-4-cyclopentene-1,3-dione

• 分子结构分类: 有机化合物 - 有机氧化合物
• 英文名称: 4,5-diethoxy-2-methyl-4-cyclopentene-1,3-dione
• 英文别名: 4,5-Diethoxy-2-methylcyclopent-4-ene-1,3-dione
• 化学式: C₁₀H₁₄O₄
• 分子量: 198.219
• InChiKey: IAUZLLVKVTWVHS-UHFFFAOYSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  1.6
• 重原子数：
  14
• 可旋转键数：
  4
• 环数：
  1.0
• sp3杂化的碳原子比例：
  0.6
• 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：

  方酸二乙酯 在 1-氧化-2-巯基吡啶 、 N,N'-二环己基碳二亚胺 作用下， 以 四氢呋喃 、 二氯甲烷 为溶剂， 反应 5.0h， 生成 4,5-diethoxy-2-methyl-4-cyclopentene-1,3-dione
  参考文献：
  名称：

  Radical-mediated ring enlargement of cyclobutenones: new synthetic potential of squaric acid.

  摘要：

  4-Hydroxy-2-cyclobutenones, which are readily obtainable from diethyl squarate, reacted with lead tetraacetate to give 5-acetoxy-2(5H)-furanones and 5-alkylidene-2(5H)-furanones via oxy-radical-triggered ring opening (beta-scission) and subsequent 5-endo reclosure. This method was extended to saturated four-membered alpha-ketol and applied to the synthesis of a natural product (Z-isomer of multicolanate). A carbon-centered radical-triggered reaction was also performed in which photolysis of a mixed anhydride of thiohydroxamic acid and (4-oxo-2-cyclobutenyl)acetic acid afforded a 4-cyclopentene-1,3-dione rather than the furanone as a rearranged product. The similarity of these rearrangements is discussed using a PM3 calculation in terms of pentadienoyl radical to cyclopentenone radical cyclization and its oxa version.

  DOI：

  10.1021/ja00143a006

文献信息

• Radical-mediated ring enlargement of cyclobutenones: new synthetic potential of squaric acid.
  作者：Yoshihiko Yamamoto、Masatomi Ohno、Shoji Eguchi

  DOI：10.1021/ja00143a006

  日期：1995.9

  4-Hydroxy-2-cyclobutenones, which are readily obtainable from diethyl squarate, reacted with lead tetraacetate to give 5-acetoxy-2(5H)-furanones and 5-alkylidene-2(5H)-furanones via oxy-radical-triggered ring opening (beta-scission) and subsequent 5-endo reclosure. This method was extended to saturated four-membered alpha-ketol and applied to the synthesis of a natural product (Z-isomer of multicolanate). A carbon-centered radical-triggered reaction was also performed in which photolysis of a mixed anhydride of thiohydroxamic acid and (4-oxo-2-cyclobutenyl)acetic acid afforded a 4-cyclopentene-1,3-dione rather than the furanone as a rearranged product. The similarity of these rearrangements is discussed using a PM3 calculation in terms of pentadienoyl radical to cyclopentenone radical cyclization and its oxa version.