2-acetyl-4-methyl-glutaric acid diethyl ester | 62718-06-3

• 分子结构分类: 有机化合物 - 有机酸及其衍生物 - 酮酸及其衍生物
• 英文名称: 2-acetyl-4-methyl-glutaric acid diethyl ester
• 英文别名: 2-Acetyl-4-methyl-glutarsaeure-diaethylester；Diethyl 2-acetyl-4-methylpentanedioate；diethyl 2-acetyl-4-methylpentanedioate
• CAS: 62718-06-3
• 化学式: C₁₂H₂₀O₅
• 分子量: 244.288
• InChiKey: SGBMTVMFIMZKJV-UHFFFAOYSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  1.5
• 重原子数：
  17
• 可旋转键数：
  9
• 环数：
  0.0
• sp3杂化的碳原子比例：
  0.75
• 拓扑面积：
  69.7
• 氢给体数：
  0
• 氢受体数：
  5

反应信息

• 作为反应物：
  描述：

  2-acetyl-4-methyl-glutaric acid diethyl ester 在 甲醇 、 sodium bromide 作用下， 以74%的产率得到2-甲基戊二酸二乙酯
  参考文献：
  名称：

  Electrochemical Deacetylation of 1,3-Dicarbonyl Compounds

  摘要：

  通过卤锪离子介导的电解，成功实现了1,3-二羰基化合物的温和去乙酰化。在此反应中，支持电解质的包含钠卤化物NaX（X = Cl或Br）是至关重要的，因为反应通过阳极电化学生成的卤锪离子在活性次甲基碳上的取代进行，紧接着是碱催化的去乙酰化，并在阴极通过还原脱卤终止于形成的α-卤代羰基化合物。

  DOI：

  10.1246/cl.1996.143
• 作为产物：
  描述：

  乙酰乙酸乙酯 、 甲基丙烯酸乙酯 在 sodium ethanolate 作用下， 生成 2-acetyl-4-methyl-glutaric acid diethyl ester
  参考文献：
  名称：

  Mechanism and Stereospecificity of a Fully Saturating Polyketide Synthase Module: Nanchangmycin Synthase Module 2 and Its Dehydratase Domain

  摘要：

  Recombinant nanchangmycin synthase module 2 (NANS module 2), with the thioesterase domain from the 6-deoxyerythronolide B synthase (DEBS TE) appended to the C-terminus, was cloned and expressed in Escherichia coli. Incubation of NANS module 2+TE with (+/-)-2-methyl-3-keto-butyryl-N-acetylcysteamine thioester (1), the SNAC analog of the natural ACP-bound substrate, with methylmalonyl-CoA (MM-CoA) in the absence of NADPH gave 3,5,6-trimethy1-4-hydroxypyrone (2), identified by direct comparison with synthetic 2 by radio-TLC-phosphorimaging and LC-ESI(+)-MS-MS. The reaction showed K(cat) 0.5 +/- 0.1 min(-1) and K(m)(1) 19 +/- 5 mM at 0.5 mM MM-CoA and k(cat)(app) 0.26 +/- 0.02 min(-1) and K(m)(MM-CoA) 0.11 +/- 0.02 mM at 8 mM 1. Incubation in the presence of NADPH generated the fully saturated triketide chain elongation product as a 5:3 mixture of (2S,4R)-2,4-dimethy1-5-ketohexanoic acid (3a) and the diastereomeric (2S, 4S)-3b. The structure and stereochemistry of each product was established by comparison with synthetic 3a and 3b by a combination of radio-TLC-phosphorimaging and LC-ESI(-)-MS-MS, as well as chiral capillary GC-MS analysis of the corresponding methyl esters 3a-Me and 3b-Me. The recombinant dehydratase domain from NANS module 2, NANS DH2, was shown to catalyze the formation of an (E)-double bond by syndehydration of the ACP-bound substrate anti-(2R,3R,4S,5R)-2,4-dimethyl-3,5-dihydroxyheptanoyl-ACP6 (4), generated in situ by incubation of (2S,3R)-2-methyl-3-hydroxypentanoyl-SNAC (5), methylmalonyl-CoA, and NADPH with the recombinant [KS6][AT6] didomain and ACP6 from DEBS module 6 along with the ketoreductase from the tylactone synthase module 1 (TYLS KR1). These results also indirectly establish the stereochemistry of the reactions catalyzed by the KR and enoylreductase (ER) domains of NANS module 2.

  DOI：

  10.1021/ja1073432

文献信息

• Ruzicka, Helvetica Chimica Acta, 1919, vol. 2, p. 155
  作者：Ruzicka

  DOI：——

  日期：——
• Electrochemical Deacetylation of 1,3-Dicarbonyl Compounds
  作者：Kazuo Fujimoto、Hirofumi Maekawa、Yoshiharu Matsubara、Ikuzo Nishiguchi

  DOI：10.1246/cl.1996.143

  日期：1996.2

  Mild deacetylation of 1,3-dicarbonyl compounds was achieved by halonium-ion mediated electrolysis. In this reaction, the supporting electrolyte including sodium halide NaX (X = Cl or Br) was essential since the reaction proceeded through substitution by a halonium ion, generated electrochemically at anode, on active methine carbons followed by base-catalyzed deacetylation, and was terminated by reductlve dehalogenation of the formed α-halo carbonyl compounds at cathode.

  通过卤锪离子介导的电解，成功实现了1,3-二羰基化合物的温和去乙酰化。在此反应中，支持电解质的包含钠卤化物NaX（X = Cl或Br）是至关重要的，因为反应通过阳极电化学生成的卤锪离子在活性次甲基碳上的取代进行，紧接着是碱催化的去乙酰化，并在阴极通过还原脱卤终止于形成的α-卤代羰基化合物。
• Mechanism and Stereospecificity of a Fully Saturating Polyketide Synthase Module: Nanchangmycin Synthase Module 2 and Its Dehydratase Domain
  作者：Xun Guo、Tiangang Liu、Chiara R. Valenzano、Zixin Deng、David E. Cane

  DOI：10.1021/ja1073432

  日期：2010.10.27

  Recombinant nanchangmycin synthase module 2 (NANS module 2), with the thioesterase domain from the 6-deoxyerythronolide B synthase (DEBS TE) appended to the C-terminus, was cloned and expressed in Escherichia coli. Incubation of NANS module 2+TE with (+/-)-2-methyl-3-keto-butyryl-N-acetylcysteamine thioester (1), the SNAC analog of the natural ACP-bound substrate, with methylmalonyl-CoA (MM-CoA) in the absence of NADPH gave 3,5,6-trimethy1-4-hydroxypyrone (2), identified by direct comparison with synthetic 2 by radio-TLC-phosphorimaging and LC-ESI(+)-MS-MS. The reaction showed K(cat) 0.5 +/- 0.1 min(-1) and K(m)(1) 19 +/- 5 mM at 0.5 mM MM-CoA and k(cat)(app) 0.26 +/- 0.02 min(-1) and K(m)(MM-CoA) 0.11 +/- 0.02 mM at 8 mM 1. Incubation in the presence of NADPH generated the fully saturated triketide chain elongation product as a 5:3 mixture of (2S,4R)-2,4-dimethy1-5-ketohexanoic acid (3a) and the diastereomeric (2S, 4S)-3b. The structure and stereochemistry of each product was established by comparison with synthetic 3a and 3b by a combination of radio-TLC-phosphorimaging and LC-ESI(-)-MS-MS, as well as chiral capillary GC-MS analysis of the corresponding methyl esters 3a-Me and 3b-Me. The recombinant dehydratase domain from NANS module 2, NANS DH2, was shown to catalyze the formation of an (E)-double bond by syndehydration of the ACP-bound substrate anti-(2R,3R,4S,5R)-2,4-dimethyl-3,5-dihydroxyheptanoyl-ACP6 (4), generated in situ by incubation of (2S,3R)-2-methyl-3-hydroxypentanoyl-SNAC (5), methylmalonyl-CoA, and NADPH with the recombinant [KS6][AT6] didomain and ACP6 from DEBS module 6 along with the ketoreductase from the tylactone synthase module 1 (TYLS KR1). These results also indirectly establish the stereochemistry of the reactions catalyzed by the KR and enoylreductase (ER) domains of NANS module 2.