3,4-diethyl-hexane-2,5-dione | 91139-83-2

• 分子结构分类: 有机化合物 - 有机氧化合物
• 英文名称: 3,4-diethyl-hexane-2,5-dione
• 英文别名: 3,4-Diethyl-2,5-hexanedione；3,4-diethylhexane-2,5-dione
• CAS: 91139-83-2
• 化学式: C₁₀H₁₈O₂
• 分子量: 170.252
• InChiKey: WTQCNKKZKCLSLA-UHFFFAOYSA-N

物化性质

• 沸点：
  112-115 °C(Press: 20 Torr)
• 密度：
  0.902±0.06 g/cm3(Temp: 20 °C; Press: 760 Torr)(Predicted)

计算性质

• 辛醇/水分配系数(LogP)：
  1.4
• 重原子数：
  12
• 可旋转键数：
  5
• 环数：
  0.0
• sp3杂化的碳原子比例：
  0.8
• 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：

  3,4-diethyl-hexane-2,5-dione 在 对甲苯磺酸 作用下， 以 苯 为溶剂， 反应 1.0h， 以70%的产率得到2,5-dimethyl-3,4-diethylfuran
  参考文献：
  名称：

  Intermediates in the Paal-Knorr Synthesis of Furans

  摘要：

  New experimental evidence for the mechanism of the Paal-Knorr reaction involving the acid-catalyzed cyclization of a 1,4-diketone to form a furan is reported. In aqueous or alcoholic solutions containing hydrochloric acid and in chloroform containing boron trifluoride-etherate d,l- and meso-3,4-diethyl-2,5-hexanediones (2r and 2m) cyclize at unequal rates; the stereochemical configuration of the unchanged done is preserved during the reaction. This disagrees with the commonly accepted mechanism involving the ring closure of the rapidly formed monoenol (11b) followed by loss of water. A pathway involving the rapid protonation of one of the carbonyls followed by the electrophilic attack on the protonated carbonyl by the enol being formed at the other carbonyl group (10c) is proposed to account for the difference in reaction rates between the diastereomers of 3,4-disubstituted 2,5-hexanediones (1-3). The following results also seem to support the intermediacy of 10c. The presence of two isopropyl groups in 3,4-diisopropyl-2,5-hexanedione (3) considerably reduces the rate of cyclization, The catalytic constants k(H)(+) for the cyclization of 2r and 2m are larger than the constants for enolization of methyl ketones. The diastereomers of 2,3-dimethyl-and 2,3-diethyl-1,4-diphenyl-1,4-butanediones (4 and 5), which could enolize only toward the center of the molecule, also react at different rates. The d,l and meso dideuterio analogs (d(2)-4r and d(2)-4m) exhibit a primary isotope effect during cyclization. The order of cyclization of 1,4-diphenyl-1,4-butanedione (6) and its analogs (7-9) reveals that the presence of electron-donating groups facilitate the reaction.

  DOI：

  10.1021/jo00107a006
• 作为产物：
  描述：

  2-戊酮 在 lead dioxide 作用下， 生成 3,4-diethyl-hexane-2,5-dione
  参考文献：
  名称：

  Reactions of Methyl-substituted 1,4-Epoxy-1,4-dihydronaphthalenes

  摘要：

  DOI：

  10.1021/jo01036a034

文献信息

• Chkir, Moncef; Lelandais, Daniel; Bacquet, Cathy, Canadian Journal of Chemistry, 1981, vol. 59, p. 945 - 951
  作者：Chkir, Moncef、Lelandais, Daniel、Bacquet, Cathy

  DOI：——

  日期：——
• Synthese de γ-dicetones symetriques par reaction de kolbe
  作者：D. Lelandais、M. Chkir

  DOI：10.1016/s0040-4039(01)91836-2

  日期：1974.1
• Stereoisomer effects on the Paal-Knorr synthesis of pyrroles
  作者：Gyongyi Szakal-Quin、Doyle G. Graham、David S. Millington、David A. Maltby、Andrew T. McPhail

  DOI：10.1021/jo00355a010

  日期：1986.3
• Intermediates in the Paal-Knorr synthesis of pyrroles
  作者：Venkataraman Amarnath、Douglas C. Anthony、Kalyani Amarnath、William M. Valentine、Lawrence A. Wetterau、Doyle G. Graham

  DOI：10.1021/jo00024a040

  日期：1991.11

  The mechanism of Paal-Knorr reaction between a 1,4-dicarbonyl compound and ammonia or a primary amine to form a pyrrole is explored. In aprotic solvents and in aqueous solutions near neutrality, d,l diastereomers of 3,4-dimethyl- and 3,4-diethyl-2,5-hexanediones (1r and 2r) formed pyrroles 1.3-57.0 times faster than the corresponding meso diastereomers (1m and 2m). This contradicts any intermediate, such as the enamine 15, which does not remain saturated at both the 3- and 4-positions through the rate-determining step. The demonstrated stereoisomeric difference in reactivity coupled with the following results support the hemiaminal (9) as the intermediate undergoing cyclization in the rate-limiting step of the Paal-Knorr reaction: (1) The reaction rate was adversely affected by increase in the size of the alkyl substituents on the dione. (2) Racemic 2,3-dimethyl-1,4-diphenyl-1,4-butanedione (3r) was more reactive toward ammonium acetate (2.2:1) and 2-aminoethanol (11.2:1) than the meso isomer (3m), ruling out the involvement of the less substituted enamine 14. (3) The relative rate of pyrrole formation of 1,4-diphenyl-1,4-butanedione (5) and its dimethoxy (6) and dinitro (7) derivatives (1:03:6) does not support cyclization of the imine (11) to the pyrrolinium ion (12). (4) The rates of reaction of 2,2,3,3-tetradeuterio-1,4-diphenyl-1,4-butanedione (5D) and perdeuterio-2,5-hexanedione (4D) were very close to those of unlabeled diketones, indicating the absence of a primary isotope effect in the reaction. (5) Neither the isomerization of the unreacted diastereomers of 1, 2, and 3 nor hydrogen exchange of 4D and 5D was detected during the reaction.
• Reactions of Methyl-substituted 1,4-Epoxy-1,4-dihydronaphthalenes
  作者：Enno Wolthuis、Byron Bossenbroek、Gordon DeWall、Edwin Geels、Arie Leegwater

  DOI：10.1021/jo01036a034

  日期：1963.1