(+)-(2S,4R)-methyl 2,4-dimethyl-5-oxohexanoate | 102849-17-2

• 分子结构分类: 有机化合物 - 脂质和类脂质分子 - 脂肪酰基
• 英文名称: (+)-(2S,4R)-methyl 2,4-dimethyl-5-oxohexanoate
• 英文别名: methyl (2S,4R)-2,4-dimethyl-5-oxohexanoate
• CAS: 102849-17-2
• 化学式: C₉H₁₆O₃
• 分子量: 172.224
• InChiKey: WYMXWWVNBWXMLN-RQJHMYQMSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  1.2
• 重原子数：
  12
• 可旋转键数：
  5
• 环数：
  0.0
• sp3杂化的碳原子比例：
  0.78
• 拓扑面积：
  43.4
• 氢给体数：
  0
• 氢受体数：
  3

反应信息

• 作为反应物：
  描述：

  (+)-(2S,4R)-methyl 2,4-dimethyl-5-oxohexanoate 在 吡啶 、 lithium hydroxide 、 sodium hydroxide 、 copper(l) iodide 、 lithium aluminium tetrahydride 、 正丁基锂 、 sodium amalgam 、 草酰氯 、 三丁基膦 、 四丁基氟化铵 、 4-甲基苯磺酸吡啶 、 碳酸氢钠 、 二异丙胺 、 间氯过氧苯甲酸 作用下， 以 四氢呋喃 、 甲醇 、 乙醚 、 二氯甲烷 、 水 、 乙酸乙酯 、 丙酮 、 苯 为溶剂， 反应 87.09h， 生成 Sodium; (12E,16E,20E)-(2S,3R,4R,5S,6R,7S,18S,22S,24R)-16-ethyl-5,7-dihydroxy-3-methoxy-2,4,6,12,18,22,24-heptamethyl-9,25-dioxo-hexacosa-12,16,20-trienoate
  参考文献：
  名称：

  莫能菌素 A 的倒数第二个生物合成三烯中间体的合成

  摘要：

  Synthese de l'acide (dihydroxy-5,7 dioxo-9,25ethyl-16 heptamethyl-2,4,6,12,18,22,24 methoxy-3) hexacosatriene-12,16,20oique par copulation de 3 synthons希罗

  DOI：

  10.1021/ja00275a055
• 作为产物：
  描述：

  2-methyl-3-ketobutyric acid-N-acetylcysteamine thioester 在 thioesterase 、 nanchangmycin synthase module 2 、 还原型辅酶II(NADPH)四钠盐 、 甲基丙二酰-辅酶A 作用下， 以 甲醇 为溶剂， 反应 0.5h， 生成 (+)-(2S,4R)-methyl 2,4-dimethyl-5-oxohexanoate
  参考文献：
  名称：

  Essential Role of the Donor Acyl Carrier Protein in Stereoselective Chain Translocation to a Fully Reducing Module of the Nanchangmycin Polyketide Synthase

  摘要：

  Incubation of recombinant module 2 of the polyether nanchangmycin synthase (NANS), carrying an appended thioesterase domain, with the ACP-bound substrate (2RS)-2-methyl-3-ketobutyryl-NANS_ACP1 (2-ACP1) and methylmalonyl-CoA in the presence of NADPH gave diastereomerically pure (25,4R)-2,4-dimethyl-5-ketohexanoic acid (4a). These results contrast with the previously reported weak discrimination by NANS module 2+TE between the enantiomers of the corresponding N-acetylcysteamine-conjugated substrate analogue (+/-)-2-methyl-3-ketobutyryl-SNAC (2-SNAC), which resulted in formation of a 5:3 mixture of 4a and its (2S,4S)-diastereomer 4h. Incubation of NANS module 2+TE with 2-ACP1 in the absence of NADPH gave unreduced 3,5,6-trimethyl-4-hydroxypyrone (3) with a K-cat of 4.4 +/- 0.9 min(-1) and a k(cat)/K-m of 67 min(-1) mM(-1), corresponding to a similar to 2300-fold increase compared to the k(cat)/K-m for the diffusive substrate 2-SNAC. Covalent tethering of the 2-methyl-3-ketobutyryl thioester substrate to the NANS ACP1 domain derived from the natural upstream PKS module of the nanchangmycin synthase significantly enhanced both the stereospecificity and the kinetic efficiency of the sequential polyketide chain translocation and condensation reactions catalyzed by the ketosynthase domain of NANS module 2.

  DOI：

  10.1021/bi201768v

文献信息

• Catalyst-Controlled Aliphatic C–H Oxidations with a Predictive Model for Site-Selectivity
  作者：Paul E. Gormisky、M. Christina White

  DOI：10.1021/ja407388y

  日期：2013.9.25

  Selective aliphatic C-H bond oxidations may have a profound impact on synthesis because these bonds exist across all classes of organic molecules. Central to this goal are catalysts with broad substrate scope (small-molecule-like) that predictably enhance or overturn the substrate's inherent reactivity preference for oxidation (enzyme-like). We report a simple small-molecule, non-heme iron catalyst that

  选择性脂肪族 CH 键氧化可能对合成产生深远的影响，因为这些键存在于所有类别的有机分子中。该目标的核心是具有广泛底物范围（类小分子）的催化剂，其可预见地增强或推翻底物对氧化（类酶）的固有反应偏好。我们报告了一种简单的小分子非血红素铁催化剂，它在一系列拓扑不同的底物上以制备产率实现了可预测的催化剂控制的位点选择性。催化剂反应模型定量地将底物的固有物理性质与观察到的位点选择性相关联，作为催化剂的函数。
• Selective Aliphatic C-H Oxidation
  申请人：White M. Christina

  公开号：US20110015397A1

  公开（公告）日：2011-01-20

  A composition including a complex of a metal, a tetradentate ligand, at least one ancillary ligand, and a counterion may be used for selective sp 3 C—H bond oxidation. The tetradentate ligand may include a N-heterocyclic-N,N′-bis(pyridyl)-ethane-1,2-diamine group or a N,N′-bis(heterocyclic)-N,N′-bis(pyridyl)-ethane-1,2-diamine group. The composition can be used in combination with H 2 O 2 to effect highly selective oxidations of unactivated sp 3 C—H bonds over a broad range of substrates. The site of oxidation can be predicted, based on the electronic and/or steric environment of the C—H bond. In addition, the oxidation reaction does not require the presence of directing groups in the substrate.

  一种包括金属复合物、四齿配体、至少一种辅助配体和对离子的组合物可用于选择性氧化sp3C—H键。四齿配体可能包括N-杂环-N,N′-双(吡啶基)-乙烷-1,2-二胺基团或N,N′-双(杂环)-N,N′-双(吡啶基)-乙烷-1,2-二胺基团。该组合物可与H2O2结合使用，对广泛范围的底物进行高度选择性的氧化未活化的sp3C—H键。可以根据C—H键的电子和/或立体环境预测氧化位置。此外，氧化反应不需要底物中存在导向基团。
• Catalyst-controlled aliphatic C—H oxidations
  申请人：The Board of Trustees of the University of Illinois

  公开号：US09925528B2

  公开（公告）日：2018-03-27

  The invention provides simple small molecule, non-heme iron catalyst systems with broad substrate scope that can predictably enhance or overturn a substrate's inherent reactivity preference for sp3-hybridized C—H bond oxidation. The invention also provides methods for selective aliphatic C—H bond oxidation. Furthermore, a structure-based catalyst reactivity model is disclosed that quantitatively correlates the innate physical properties of the substrate to the site-selectivities observed as a function of the catalyst. The catalyst systems can be used in combination with oxidants such as hydrogen peroxide to effect highly selective oxidations of unactivated sp3 C—H bonds over a broad range of substrates.

  该发明提供了一种简单的小分子、非血红素铁催化体系，具有广泛的底物范围，可以可预测地增强或颠覆底物对sp3杂化C-H键氧化的固有反应性偏好。该发明还提供了选择性脂肪族C-H键氧化的方法。此外，还披露了一种基于结构的催化剂反应性模型，该模型定量地相关底物的固有物理性质与作为催化剂功能的位选择性。这些催化体系可以与过氧化氢等氧化剂结合使用，对广泛的底物范围上的未活化的sp3 C-H键进行高度选择性的氧化。
• Rhodium-Catalyzed Enantioselective Desymmetrization of <i>meso</i>-3,5-Dimethyl Glutaric Anhydride:  A General Strategy to <i>syn</i>-Deoxypolypropionate Synthons
  作者：Matthew J. Cook、Tomislav Rovis

  DOI：10.1021/ja073269s

  日期：2007.8.1

  A rhodium phosphinooxazoline system allows for an efficient enantioselective desymmetrization of dimethyl glutaric anhydride. Both commercially available and in situ generated sp3-organozinc nucleophiles couple efficiently in high enantiomeric excess. This chemistry has also been extended to other 3,5-disubstituted anhydrides, and further elaboration has enabled the synthesis of potentially useful

  铑膦基恶唑啉系统允许二甲基戊二酸酐的有效对映选择性去对称化。市售的和原位生成的 sp3-organozinc 亲核试剂在高对映体过量情况下有效地偶联。这种化学反应也已扩展到其他 3,5-二取代酸酐，进一步的研究使合成可能有用的顺-脱氧聚丙酸酯片段成为可能。
• Elucidation of the Cryptic Methyl Group Epimerase Activity of Dehydratase Domains from Modular Polyketide Synthases Using a Tandem Modules Epimerase Assay
  作者：Xinqiang Xie、Ashish Garg、Chaitan Khosla、David E. Cane

  DOI：10.1021/jacs.7b05502

  日期：2017.7.19

  Dehydratase (DH) domains of cryptic function are often found in polyketide synthase (PKS) modules that produce epimerized (2S)-2-methyl-3-ketoacyl-ACP (acyl carrier protein) intermediates. A combination of tandem equilibrium isotope exchange (EIX) and a newly developed Tandem Modules Epimerase assay revealed the intrinsic epimerase activity of NanDH1 and NanDH5, from modules 1 and 5, respectively, of

  具有神秘功能的脱水酶 (DH) 域通常存在于聚酮合酶 (PKS) 模块中，这些模块产生差向异构化 (2S)-2-甲基-3-酮酰基-ACP（酰基载体蛋白）中间体。串联平衡同位素交换 (EIX) 和新开发的串联模块差向异构酶测定的组合揭示了分别来自模块 1 和模块 5 的 Nanchangmycin (1) PKS 以及来自模块的 NigDH1 的 NanDH1 和 NanDH5 的内在差向异构酶活性1 尼日利亚菌素 (3) PKS。出乎意料的是，所有三个表异构酶活性 DH 结构域也被发现具有内在的脱水酶活性，而传统的 DH 结构域，来自红霉素合成酶模块 4 的 EryDH4 和来自南昌霉素合成酶模块 2 的 NanDH2，被证明具有隐蔽的表异构酶活动。