2-Methyl-1-butene-1,3-dione | 132723-21-8

• 分子结构分类: 有机化合物 - 有机氧化合物
• 英文名称: 2-Methyl-1-butene-1,3-dione
• 英文别名: methylacetylketene；acetyl(methyl)ketene
• CAS: 132723-21-8
• 化学式: C₅H₆O₂
• 分子量: 98.1014
• InChiKey: ABVJXABNYINQLN-UHFFFAOYSA-N

物化性质

• 沸点：
  127.0±19.0 °C(Predicted)
• 密度：
  0.943±0.06 g/cm3(Predicted)

计算性质

• 辛醇/水分配系数(LogP)：
  0.6
• 重原子数：
  7
• 可旋转键数：
  1
• 环数：
  0.0
• sp3杂化的碳原子比例：
  0.4
• 拓扑面积：
  34.1
• 氢给体数：
  0
• 氢受体数：
  2

反应信息

• 作为反应物：
  描述：

  2-Methyl-1-butene-1,3-dione 在 水 作用下， 生成 2-甲基乙酰乙酸
  参考文献：
  名称：

  Durch sterische effekte stabilisierteß-ketocarbonsäuren

  摘要：

  β-酮基羧酸的空间位阻增加，导致脱羧的动力学稳定性增加，直至达到在室温下完全稳定的体系。同时，改变互变异构平衡以有利于（Z）-烯醇，最后有利于（E）-构型的烯醇。

  DOI：

  10.1016/s0040-4039(01)93755-4
• 作为产物：
  描述：

  (2Z)-3-偶氮基-4-氧代-2-戊烯-2-醇 以 乙醚 为溶剂， 生成 2-Methyl-1-butene-1,3-dione
  参考文献：
  名称：

  Durch sterische effekte stabilisierteß-ketocarbonsäuren

  摘要：

  β-酮基羧酸的空间位阻增加，导致脱羧的动力学稳定性增加，直至达到在室温下完全稳定的体系。同时，改变互变异构平衡以有利于（Z）-烯醇，最后有利于（E）-构型的烯醇。

  DOI：

  10.1016/s0040-4039(01)93755-4

文献信息

• Periselectivity in the aza-Diels–Alder Cycloaddition between α-Oxoketenes and <i>N</i>-(5-Pyrazolyl)imines: A Combined Experimental and Theoretical Study
  作者：Juan-Carlos Castillo、Brian Castro Agudelo、Jaime Gálvez、Yannick Carissan、Jean Rodriguez、Yoann Coquerel

  DOI：10.1021/acs.joc.0c00767

  日期：2020.6.5

  N-(5-pyrazolyl)imines as the 4π partners at their 2-azadiene moiety. In contrast, other cyclic and acyclic α-oxoketenes lead preferentially to 1,3-oxazin-4-ones, which now involves the α-oxoketenes as the 4π partners at their 1-oxadiene moiety and the N-(5-pyrazolyl)imines as the 2π partners at their C═N double bond. A computational modeling study using DFT methods allowed rationalizing this change of periselectivity:

  α-氧杂环丁烯之间的热6πaza-Diels-Alder环加成反应原位是由热诱导的2-重氮1,3-二酮的Wolff重排和N-（5-吡唑基）亚胺作为典型的富电子2-氮杂二烯产生两种不同的产物，基本上是所涉及的α-氧杂环丁烯的性质的函数。例如，环状五元α-氧杂环丁烯优先导致螺氢吡啶-4-酮，其中α-氧杂环丁烯在其C═C双键处为2π配偶体，而N-（5-吡唑基）亚胺为4π。在它们的2-氮杂二烯部分上形成伙伴。相比之下，其他环状和无环的α-氧杂环丁烯优先导致1,3-oxazin-4-ones，现在，α-氧杂环丁烯在其1 -oxadiene部分和4π伙伴中涉及4π伙伴。N-（5-吡唑基）亚胺在其C═N双键处为2π伙伴。使用DFT方法进行的计算模型研究可以合理化这种选择性的变化：螺吡喃并吡啶-4-酮的形成受热力学控制，而1,3-恶嗪-4-酮的形成受动力学控制，而在热力学上略有不利。五元环系列。还详细研究了α-氧杂环丁烯的竞争性环二聚化。
• Sato, Masayuki; Ogasawara, Hiromichi; Komatsu, Sachiko, Chemical and pharmaceutical bulletin, 1984, vol. 32, # 10, p. 3848 - 3856
  作者：Sato, Masayuki、Ogasawara, Hiromichi、Komatsu, Sachiko、Kato, Tetsuzo

  DOI：——

  日期：——
• Direct observation of .alpha.-oxo ketenes formed from 1,3-dioxin-4-ones and the enols of .beta.-keto esters
  作者：Beat Freiermuth、Curt Wentrup

  DOI：10.1021/jo00007a008

  日期：1991.3

  The enol forms of beta-keto esters thermolyze to alcohols and alpha-oxo ketenes, which are characterized by low-temperature IR spectroscopy and on warming regenerate the beta-hydroxy-alpha,beta-unsaturated esters. The matrix isolated s-Z and s-E forms of alpha-oxo ketenes are characterized and photochemically converted into other conformers or sites. Matrix photolysis of 2,2,6-trimethyl-1,3-dioxin-4-one gives the s-Z acetylketene initially. Alpha-Oxo ketenes polymerize in the cold and dimerize only at elevated temperatures.
• FREIERMUTH, BEAT;WENTRUP, CURT, J. ORG. CHEM., 56,(1991) N, C. 2286-2289
  作者：FREIERMUTH, BEAT、WENTRUP, CURT

  DOI：——

  日期：——
• Direct observation of .alpha.-oxo ketenes from the photolysis of .alpha.-diazo .beta.-diketones
  作者：Regis Leung-Toung、Curt Wentrup

  DOI：10.1021/jo00044a019

  日期：1992.8

  Monitoring by IR spectroscopy of the broad-band irradiation of the symmetrically substituted 2-diazo-cyclohexane-1,3-dione (I 1), 3-diazopentane-2,4-dione (19), and 4-diazo-2,2,6,6-tetramethylheptane-3,5-dione (24) in Ar matrices at 12 K showed the formation of 2-carbonylcyclopentanone (s-Z-12), acetyl(methyl)ketene (s-E-20), and tert-butyl(pivaloyl)ketene (s-E-25), respectively, in less than 10 min. On increasing the photolysis time to >3 h, the alpha-oxo ketenes 12,20, and 25 decarbonylated to the corresponding oxocarbenes which underwent Wolff rearrangement to carbonylcyclobutane (15), dimethylketene (23), and di-tert-butylketene (28), respectively. The reaction of 2-carbonylcyclopentanone (12) with CH3OH was monitored by IR spectroscopy. Thus, it was found that the reaction started at ca. 100 K and was essentially complete at 140 K, involving the initial formation of the enol form (9) of methyl 2-oxocyclopentanecarboxylate.