3,4,6-tri-O-pivaloyl-D-galactal

• 分子结构分类: 有机化合物 - 有机酸及其衍生物 - 羧酸及其衍生物
• 英文名称: 3,4,6-tri-O-pivaloyl-D-galactal
• 英文别名: tri-O-pivaloyl-D-galactal；[(2R,3R,4R)-3,4-bis(2,2-dimethylpropanoyloxy)-3,4-dihydro-2H-pyran-2-yl]methyl 2,2-dimethylpropanoate
• 化学式: C₂₁H₃₄O₇
• 分子量: 398.497
• InChiKey: CPUWJJIRYNLNIR-RBSFLKMASA-N

计算性质

• 辛醇/水分配系数(LogP)：
  4.4
• 重原子数：
  28
• 可旋转键数：
  10
• 环数：
  1.0
• sp3杂化的碳原子比例：
  0.76
• 拓扑面积：
  88.1
• 氢给体数：
  0
• 氢受体数：
  7

反应信息

• 作为反应物：
  描述：

  3,4,6-tri-O-pivaloyl-D-galactal 在 calcium sulfate 、 sodium dithionite 、 碳酸氢钠 、 silver carbonate 作用下， 以 水 、 乙腈 为溶剂， 反应 1.5h， 生成 2,2-Dimethyl-propionic acid (2R,3R,4R,5R,6R)-3-(bromo-difluoro-methyl)-5-(2,2-dimethyl-propionyloxy)-6-(2,2-dimethyl-propionyloxymethyl)-2-methoxy-tetrahydro-pyran-4-yl ester
  参考文献：
  名称：

  A New Method for the Selective Introduction of Difluoromethyl and Trifluoromethyl Groups into Sugar Moieties

  摘要：

  We have studied the fluoroalkylation of the glucal 1 and the galactal 4 with dibromodifluoromethane via the 2-C-bromodifluoromethyl-substituted glycosyl bromides 2 and 5, respectively, followed by glycosylation to the methyl beta-D-glycosides 3 and 6. The bromodifluoromethyl groups in the 2 position of the compounds 3 and 6 were converted into difluoromethyl and trifluoromethyl groups, respectively, giving the fluorinated monosaccharides 7-10.

  DOI：

  10.1002/(sici)1099-0690(199805)1998:5<919::aid-ejoc919>3.0.co;2-3

文献信息

• Electrophilic Fluorination−Nucleophilic Addition Reaction Mediated by Selectfluor: Mechanistic Studies and New Applications
  作者：Stéphane P. Vincent、Michael D. Burkart、Chung-Ying Tsai、Zhiyuan Zhang、Chi-Huey Wong

  DOI：10.1021/jo990686h

  日期：1999.7.1

  The electrophilic fluorination-nucleophilic addition reaction with Selectfluor-type reagents upon glycals has been studied and optimized. This reaction leads to selective fluorination at the 2-position with concomitant nucleophilic addition to the anomeric center. To understand the stereochemical outcome of this process, a mechanistic study has led to the discovery that, in the fucose series, Selectfluor

  已经研究和优化了与 Selectfluor 型试剂在糖基上的亲电氟化-亲核加成反应。该反应导致在 2 位选择性氟化，同时对异头中心进行亲核加成。为了了解该过程的立体化学结果，一项机制研究发现，在岩藻糖系列中，Selectfluor 以顺式方式特异性添加，产生 1-[TEDA-CH2Cl]-2-氟糖，该糖缓慢异构化为更稳定的中间体。研究了异头α/β分布作为反应物和条件的函数，发现保护基策略的明智选择可以提高氟化和亲核加成的立体选择性。此外，使用超敏自由基探针来探测反应，并且没有分离出自由基过程的产物特征，这表明在聚糖对 Selectfluor 的攻击期间没有发生单电子转移。还讨论了溶剂效应、Selectfluor 反离子和逐步程序的重要性。这项研究带来了产量的重要改进和更广泛的允许亲核试剂，如碳水化合物、氨基酸、磷酸盐或膦酸盐的仲醇。这一优化过程进一步应用于重要生物活性分子的修饰，包括氟化道
• Palladium-Catalyzed Direct Cross-Coupling Reaction of Glycals with Activated Alkenes
  作者：Yaguang Bai、Jing Zeng、Shuting Cai、Xue-Wei Liu

  DOI：10.1021/ol201734w

  日期：2011.8.19

  cross-coupling reaction of glycals with activated alkenes under mild conditions has been developed. This transformation provides an expedient synthetic method to C(2)-functionalized glycals, which are common structural building blocks in natural products and other biologically active compounds. The reaction scope includes different kinds of carbohydrates, protecting groups and substituents on alkene. Moderate

  已开发出一种在温和条件下Pd（OAc）2催化的糖类与活化烯烃的交叉偶联反应的有效方法。这种转变为C（2）-功能化的糖类提供了一种方便的合成方法，这些糖类是天然产物和其他生物活性化合物中的常见结构构件。反应范围包括不同种类的碳水化合物，烯烃上的保护基和取代基。获得了中等至优异的产率和纯的E构型选择性。
• Stereoselective propargylation of glycals with allenyltributyltin(IV) via a Ferrier type reaction
  作者：Mark D. Drew、Mark C. Wall、Joseph T. Kim

  DOI：10.1016/j.tetlet.2012.03.115

  日期：2012.6

  Stereoselective introduction of an unsubstituted propargyl group to various glycals was achieved using a Ferrier type reaction with allenyltributyltin(IV). The stereoselectivity was observed based on the conformational preference of glycals as well as steric control of rigid bicyclic systems.

  使用与烯丙基三丁基锡（IV）的Ferrier型反应，可将未取代的炔丙基立体选择性地引入各种糖基。基于糖基的构象偏好以及刚性双环系统的空间控制，观察到立体选择性。
• Stereoselective Tandem Epoxidation-Alcoholysis/Hydrolysis of Glycals with Molybdenum Catalysts
  作者：Irene Marín、M. Isabel Matheu、Yolanda Díaz、Sergio Castillón

  DOI：10.1002/adsc.201000614

  日期：2010.12.17

  Molybdenum catalysts are efficient and selective catalysts for the tandem epoxidation/alcoholysis or epoxidation/hydrolysis of glucal and galactal derivatives. In glucal derivatives the selectivity is mainly controlled by the allylic substituent at position 3 of the glycal, obtaining in general the products derived from the initial formation of the α-epoxide (gluco) when this hydroxy group is protected, while

  钼催化剂是用于葡糖和半乳糖衍生物的串联环氧化/醇解或环氧化/水解的有效且选择性的催化剂。在葡糖衍生物中，选择性主要受糖基位置3上的烯丙基取代基控制，通常获得在羟基被保护时最初衍生自α-环氧化物（葡萄糖）的产物，而衍生自β的产物。 -环氧化物（甘露）主要是在未保护的情况下获得的。在半乳衍生物中，酯选择性始终很高，可以得到α-环氧化物（半乳酸酯），并且与保护基团无关。
• Trifluoromethylation of Electron-Rich Alkenyl Iodides with Fluoroform-Derived “Ligandless” CuCF₃
  作者：Jordi Mestre、Anton Lishchynskyi、Sergio Castillón、Omar Boutureira

  DOI：10.1021/acs.joc.8b00927

  日期：2018.8.3

  We herein present a flexible approach for the incorporation of CF3 units into a predefined site of electron-rich alkenes that exploits the regiocontrolled introduction of an iodine handle and subsequent trifluoromethylation of the C(sp2)–I bond using fluoroform-derived “ligandless” CuCF3. The broad substrate scope and functional group tolerance together with the scalability and purity of the resulting

  我们在此提出了一种将CF 3单元并入富含电子的烯烃的预定位点的灵活方法，该方法利用了碘控制的区域控制性引入以及随后使用氟仿衍生的“无配位体”对C（sp 2）-I键进行了三氟甲基化。” CuCF 3。广泛的底物范围和官能团耐受性以及所得产品的可扩展性和纯度使复杂的CF 3支架（如糖，核苷（抗病毒剂）和杂环（吲哚和色酮），具有学术和工业应用潜力。