methyl 2,3-O-isopropylidene-β-D-xylopyranoside | 118203-99-9

• 分子结构分类: 有机化合物 - 有机氧化合物
• 英文名称: methyl 2,3-O-isopropylidene-β-D-xylopyranoside
• 英文别名: (3aR,4R,7R,7aS)-4-methoxy-2,2-dimethyl-4,6,7,7a-tetrahydro-3aH-[1,3]dioxolo[4,5-c]pyran-7-ol
• CAS: 118203-99-9
• 化学式: C₉H₁₆O₅
• 分子量: 204.223
• InChiKey: YJRSYLLAIOOPEJ-ULAWRXDQSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  -0.4
• 重原子数：
  14
• 可旋转键数：
  1
• 环数：
  2.0
• sp3杂化的碳原子比例：
  1.0
• 拓扑面积：
  57.2
• 氢给体数：
  1
• 氢受体数：
  5

反应信息

• 作为反应物：
  描述：

  methyl 2,3-O-isopropylidene-β-D-xylopyranoside 在 吡啶 、 溶剂黄146 作用下， 以 二氯甲烷 、 水 为溶剂， 反应 18.0h， 生成 methyl 4-O-acetyl-β-D-xylopyranoside
  参考文献：
  名称：

  通过实验和计算方法研究吡喃糖苷中的酰基迁移。

  摘要：

  酰基迁移影响所有含有游离羟基的酰化有机化合物，特别是碳水化合物的合成、分离、操作和纯化。虽然已经报道了一些关于不同缓冲液中迁移现象的孤立研究，但缺乏对类似条件下不同单糖整体迁移过程的全面了解。在这里，我们结合实验、动力学和理论工具，使用五种不同的酰基研究了不同单糖中的酰基迁移。结果表明，单糖中的异头构型与其他羟基的相对构型和迁移酰基的性质一起对迁移速率有重大影响。全机械模型，基于计算，

  DOI：

  10.1002/chem.202200499
• 作为产物：
  描述：

  methyl 2,3-O-isopropylidene-4-O-(1-methoxy-1-methylethyl)-β-D-xylopyranoside 在 甲醇 、 对甲苯磺酸 作用下， 反应 0.17h， 以81.4%的产率得到methyl 2,3-O-isopropylidene-β-D-xylopyranoside
  参考文献：
  名称：

  Regioselective protection strategies for D-xylopyranosides

  摘要：

  The acylation of D-xylopyranosides can be effected at any position by selective hydroxyl activation with dibutyltin oxide in refluxing benzene and proper choice of starting anomer. Methyl 4-O-benzyl-beta-D-xylopyranoside, available from methyl 2,3-O-isopropylidene-beta-D-xylopyranoside, provides the 2- and 3-benzoates, which are easily separable in 85% combined yield. Methyl and allyl beta-D-xylopyranosides, when treated with 1 equiv of dibutyltin and subsequently with benzoyl chloride (1 equiv), yield their corresponding 4-benzoates (80%). The use of 2 equiv of benzoyl chloride provides the 3,4-dibenzoates in excellent yield (90%). The clean conversion to mono- or dibenzoates, depending on the amount of benzoyl chloride added, suggests that the intermediate stannylene acetals provide different activation levels. A pathway involving acylation of an intermediate dibutylchlorostannyl ether is proposed to explain the observed phenomenon. This sequential selective activation is used to afford protection and differentiation of the 3- and 4-positions with a one-pot synthesis of methyl 4-O-benzoyl-3-O-(chloroacetyl)-beta-D-xylopyranoside. Methyl and benzyl alpha-D-xylopyranosides afford the 2,4-dibenzoates in good yield (> 80%) demonstrating 1,3-activation of a triol system. This protection strategy is used to prepare benzyl O-(2,3,5-tri-O-benzoyl-alpha-L-arabinofuranosyl)-(1 --> 3)-2,4-di-O-benzoyl-alpha-D-xylopyranoside from D-xylose and L-arabinose. In the final step, the silver triflate catalyzed glycosylation of benzyl 2,4-di-O-benzoyl-alpha-D-xylopyranoside by 2,3,5-tri-O-benzoyl-alpha-L-arabinofuranosyl chloride is accomplished in 91% yield.

  DOI：

  10.1021/jo00025a013

文献信息

• A convenient synthesis of 4-amino-4-deoxy-l-arabinose and its reduction product, 1,4-dideoxy-1,4-imino-l-arabinitol
  作者：John J. Naleway、Christian R.H. Raetz、Laurens Anderson

  DOI：10.1016/0008-6215(88)84118-1

  日期：1988.8

  Methyl 2,3-di-O-acetyl-4-azido-4-deoxy-alpha-L-arabinopyranoside, from the diol, appears (1H-n.m.r. data) to exist as an equilibrating mixture of the 4C1 and 1C4 conformers in chloroform solution. The reduction of the azido sugar by hydrogen over Pd/C in .6M HCl yielded 4-amino-4-deoxy-L-arabinopyranose as its hydrochloride; in 0.1M HCl, further reactions occurred to give 1,4-dideoxy-1,4-imino-L-arabinitol

  N，N-二甲基甲酰胺和含少量氯化氢的2-甲氧基丙烯的混合物中的甲基β-D-吡喃吡喃糖苷主要产生2,3-O-异亚丙基衍生物，该衍生物易于转化为其4-三氟甲磺酸酯。三氟甲磺酸酯基团的容易取代得到4-叠氮基-4-脱氧-α-L-阿拉伯吡喃果糖苷衍生物，在温和的酸处理下，将其水解为2,3-二醇，或在更剧烈的条件下水解为4-叠氮基-4-脱氧-L-阿拉伯糖。来自二醇的甲基2,3-二-O-乙酰基-4-叠氮基4-脱氧-α-L-阿拉伯吡喃果糖苷（1H-nmr数据）以氯仿中4C1和1C4构象异构体的平衡混合物形式存在解。在0.6M HCl中，在Pd / C上用氢还原叠氮糖，得到4-氨基-4-脱氧-L-阿拉伯吡喃葡萄糖酸盐。在0.1M HCl中 发生进一步反应，得到1,4-二脱氧-1,4-亚氨基-L-阿拉伯糖醇为最终产物。Raetz等人从沙门氏菌突变体分离的脂质A前体IIA中的氨基脱氧戊糖。1985年，TLC，1
• Synthesis and <i>O</i>-Glycosidic Linkage Conformational Analysis of ¹³C-Labeled Oligosaccharide Fragments of an Antifreeze Glycolipid
  作者：Wenhui Zhang、Reagan Meredith、Mi-Kyung Yoon、Xiaocong Wang、Robert J. Woods、Ian Carmichael、Anthony S. Serianni

  DOI：10.1021/acs.joc.8b01411

  日期：2019.2.15

  NMR studies of two 13C-labeled disaccharides and a tetrasaccharide were undertaken that comprise the backbone of a novel thermal hysteresis glycolipid containing a linear glycan sequence of alternating [βXylp-(1→4)-βManp-(1→4)]n dimers. Experimental trans-glycoside NMR J-couplings, parameterized equations obtained from density functional theory (DFT) calculations, and an in-house circular statistics

  两个NMR研究13 C标记的二糖和四糖开展了包含糖脂含交替的线性聚糖序列的新颖的热滞后的骨干[βXyl p - （1→4）-βMAn p - （1→4）] n个二聚体。实验性的反式糖苷NMR J联轴器，从密度泛函理论（DFT）计算获得的参数化方程式以及内部循环统计软件包（MA'AT）被用来导出溶液中连杆扭转角ϕ和ψ的构象模型，这些结果与从分子动力学模拟获得的结果进行了比较。使用不同的概率分布函数进行建模表明，MA'ATβMAn（1→4）βXyl和βXyl（1→4）βMAn键中的ϕ模型在二糖结构单元中非常相似，而ψ的MA'AT模型则不同。这种模式在四糖中是保守的，表明连接上下文不影响该线性系统中的连接几何形状。在ψ的MA'AT和MD模型之间，就平均值和圆标准偏差而言，观察到了很好的一致性。对于observed观察到显着差异，表明可能需要修改GLYCAM所使用的力场。将models和ψ的实验模
• Applicability of the Mosher MPTA-Ester Methodology to Monosaccharides
  作者：Matteo Adinolfi、Cristina De Castro、Alfonso Iadonisi、Rosa Lanzetta、Antonio Molinaro

  DOI：10.1080/07328309808007469

  日期：1998.8.1

  the exciton chiral coupling method to two fragments obtained by NaIO4, oxidation of the polysaccharide chain. The absolute configuration of a chiral secondary alcohol can be defined by Mosher's method.3 It analyzes the signs of the differences between the chemical shifts of the protons vicinal to the chiral Center in the (S)- and (R)-α-methoxy-α-trifluoromethylphenylacetate (MPTA) esters obtained from

  石竹糖1是一种新型的12碳4 C支链单糖，是假单胞菌拟细菌的脂多糖组分中发现的多糖链的组成部分。1通过将激子手性偶联方法应用于NaIO4得到的两个片段，阐明了其绝对立体化学。多糖链的氧化。手性仲醇的绝对构型可以通过Mosher方法进行定义。3它分析了在（S）-和（R）-α-甲氧基-中邻位质子向手性中心化学位移之间差异的征兆。由该化合物获得的α-三氟甲基苯乙酸酯（MPTA）酯。但是，当将Mosher酯方法应用于石竹纤维双双亚丙基衍生物2时，无法给出完全可靠的结果。实际上，
• Strategy for contra-thermodynamic radical-chain epimerisation of 1,2-diols using polarity-reversal catalysis
  作者：Hai-Shan Dang、Brian P. Roberts

  DOI：10.1016/s0040-4039(00)01502-1

  日期：2000.10

  Polarity-reversal catalysis by thiols has been applied to provide an efficient method for the conversion of appropriate 1,2-diols into less or similarly stable diastereoisomers by epimerisation of their acetonides under radical-chain conditions.

  已应用通过硫醇进行的极性反转催化来提供一种有效的方法，用于通过在自由基链条件下将它们的丙酮化物差向异构化，将适当的1,2-二醇转化为含量较低或类似的非对映异构体。
• Selective radical-chain epimerisation at electron-rich chiral tertiary C–H centres using thiols as protic polarity-reversal catalysts
  作者：Hai-Shan Dang、Brian P. Roberts、Derek A. Tocher†

  DOI：10.1039/b103558b

  日期：——

  Radical-chain epimerisation at chiral tertiary CH centres adjacent to ethereal oxygen atoms can be brought about in the presence of thiols, the function of which is to act as protic polarity-reversal catalysts for hydrogen-atom transfer between pairs of nucleophilic α-alkoxyalkyl radicals. The viability of the method is demonstrated by epimerisation of a series of simple molecules that contain two chiral centres and then the procedure is applied to more complex carbohydrate-based systems, where it is possible to convert a readily available diastereoisomer into a rarer one in a straightforward manner. Of necessity, epimerisation always proceeds in the direction of thermodynamic equilibrium and, in general, the results obtained are in accord with the predictions of molecular mechanics calculations using the MMX force-field. When the required isomer is less stable than the starting diastereoisomer, thiol-catalysed epimerisation of a suitable derivative of the parent can provide a means to obtain the desired compound in satisfactory yield, after deprotection of the epimerised derivative. This strategy is demonstrated for the conversion of trans-cyclohexane-1,2-diol into the less stable cis-isomer and for related contra-thermodynamic isomerisation of some carbohydrates, as well as for the conversion of meso-1,2-diphenylethane-1,2-diol into the dl-form. Thiol-catalysed epimerisation at a CH centre adjacent to an ether-oxygen atom is much faster than at a similar centre adjacent to an amido-nitrogen atom, a result that can be understood in terms of the importance of polar effects on the rate of abstraction of hydrogen by electrophilic thiyl radicals.

  硫醇的作用是作为亲核δ-烷氧基烷基自由基对之间氢原子转移的原生极性反转催化剂，可以在邻近乙氧基原子的手性三级 CH 中心实现自由基链表并化。通过对一系列含有两个手性中心的简单分子进行外延二聚化，证明了该方法的可行性，然后将该程序应用于更复杂的基于碳水化合物的体系，在这些体系中，可以通过直接的方式将容易获得的非对映异构体转化为较罕见的非对映异构体。必要时，二聚化总是朝着热力学平衡的方向进行，一般来说，所获得的结果与使用 MMX 力场进行分子力学计算的预测结果一致。当所需异构体的稳定性低于起始非对映异构体时，可采用巯基催化母体的适当衍生物进行外延化反应，在对外延化衍生物进行脱保护处理后，以令人满意的收率获得所需化合物。这种策略在反式-1,2-环己烷二醇转化为稳定性较差的顺式异构体、某些碳水化合物的相关逆热力学异构化以及介-1,2-二苯基乙烷-1,2-二醇转化为 dl-形式时得到了验证。邻近醚氧原子的 CH 中心在硫醇催化下的缩合反应要比邻近酰胺氮原子的类似中心快得多，这一结果可以从极性效应对亲电巯基取氢速率的重要性角度来理解。