methyl (methyl 2,3-di-O-benzyl-α-D-mannopyranosyluronate) | 1158840-55-1

• 分子结构分类: 有机化合物 - 有机氧化合物
• 英文名称: methyl (methyl 2,3-di-O-benzyl-α-D-mannopyranosyluronate)
• 英文别名: methyl (2S,3S,4S,5S,6S)-3-hydroxy-6-methoxy-4,5-bis(phenylmethoxy)oxane-2-carboxylate
• CAS: 1158840-55-1
• 化学式: C₂₂H₂₆O₇
• 分子量: 402.444
• InChiKey: RIOSPUQZLPCUNG-HVAMYJMISA-N

物化性质

• 沸点：
  527.1±50.0 °C(predicted)
• 密度：
  1.24±0.1 g/cm3(Temp: 20 °C; Press: 760 Torr)(predicted)

计算性质

• 辛醇/水分配系数(LogP)：
  2.6
• 重原子数：
  29
• 可旋转键数：
  9
• 环数：
  3.0
• sp3杂化的碳原子比例：
  0.41
• 拓扑面积：
  83.4
• 氢给体数：
  1
• 氢受体数：
  7

反应信息

• 作为反应物：
  描述：

  methyl (2S,3S,4S,5S,6S)-3-(4-oxopentanoyloxy)-4,5-bis(phenylmethoxy)-6-phenylsulfanyloxane-2-carboxylate 、 methyl (methyl 2,3-di-O-benzyl-α-D-mannopyranosyluronate) 在 三氟甲磺酸酐 、 二苯基亚砜 、 2,4,6-三叔丁基嘧啶 作用下， 以 二氯甲烷 为溶剂， 反应 0.25h， 以31%的产率得到methyl 2,3-di-O-benzyl-4-O-[methyl (2,3-di-O-benzyl-4-O-levulinoyl-β-D-mannopyranosyluronate)]-α-D-mannopyranosyluronate
  参考文献：
  名称：

  Stereoselectivity of glycosylations of conformationally restricted mannuronate esters

  摘要：

  Glycosidation of conformationally unrestricted mannuronate ester donors proceeds in a highly P-selective fashion, whereas condensations of mannuronate ester donors, which are con formationally constrained by a 3,4-butanedimethylacetal or a 2,3-isopropylidene function, provide a-selective products. We hypothesize that the difference in stereochemical outcome of these condensations results from the different conformations of the product forming oxacarbenium intermediate. The formation of the beta-linked products from the flexible mannuronates is thought to originate from the most favorable H-3(4) oxacarbenium ion, which is not accessible from the conformationally restrained donors. Although an a-triflate intermediate is formed upon activation of the 3,4-butanedimethylacetal protected mannuronate ester thio donor, this is not the product forming intermediate. The anomeric triflate serves as a reservoir for the H-4(3) oxacarbenium ion, which is glycosidated to provide the a-linked mannuronates. (C) 2009 Elsevier Ltd. All rights reserved.

  DOI：

  10.1016/j.tet.2009.02.067
• 作为产物：
  描述：

  methyl 2,3-di-O-benzyl-α-D-mannopyranosyluronic acid 、 碘甲烷 在 potassium carbonate 作用下， 以 N,N-二甲基甲酰胺 为溶剂， 反应 0.75h， 以723 mg的产率得到methyl (methyl 2,3-di-O-benzyl-α-D-mannopyranosyluronate)
  参考文献：
  名称：

  Stereoselectivity of glycosylations of conformationally restricted mannuronate esters

  摘要：

  Glycosidation of conformationally unrestricted mannuronate ester donors proceeds in a highly P-selective fashion, whereas condensations of mannuronate ester donors, which are con formationally constrained by a 3,4-butanedimethylacetal or a 2,3-isopropylidene function, provide a-selective products. We hypothesize that the difference in stereochemical outcome of these condensations results from the different conformations of the product forming oxacarbenium intermediate. The formation of the beta-linked products from the flexible mannuronates is thought to originate from the most favorable H-3(4) oxacarbenium ion, which is not accessible from the conformationally restrained donors. Although an a-triflate intermediate is formed upon activation of the 3,4-butanedimethylacetal protected mannuronate ester thio donor, this is not the product forming intermediate. The anomeric triflate serves as a reservoir for the H-4(3) oxacarbenium ion, which is glycosidated to provide the a-linked mannuronates. (C) 2009 Elsevier Ltd. All rights reserved.

  DOI：

  10.1016/j.tet.2009.02.067

文献信息

• Mapping the Relationship between Glycosyl Acceptor Reactivity and Glycosylation Stereoselectivity
  作者：Stefan van der Vorm、Jacob M. A. van Hengst、Marloes Bakker、Herman S. Overkleeft、Gijsbert A. van der Marel、Jeroen D. C. Codée

  DOI：10.1002/anie.201802899

  日期：2018.7.2

  The reactivity of both coupling partners—the glycosyl donor and acceptor—is decisive for the outcome of a glycosylation reaction, in terms of both yield and stereoselectivity. Where the reactivity of glycosyl donors is well understood and can be controlled through manipulation of the functional/protecting‐group pattern, the reactivity of glycosyl acceptor alcohols is poorly understood. We here present

  就产量和立体选择性而言，两个偶联伙伴（糖基供体和受体）的反应性对糖基化反应的结果都具有决定性作用。如果对糖基供体的反应性了解得很好，并且可以通过功能/保护基团模式的控制来控制，则对糖基受体醇的反应性了解得很少。我们在这里提出了一个操作简单的系统来评估糖基受体的反应性，该系统采用了两个构象锁定的供体，其立体选择性严格取决于亲核试剂的反应性。筛选了大量受体，并建立了它们的结构-反应性/立体选择性关系。通过系统地改变保护基，可以调节糖基受体的反应性以获得立体选择性。顺式葡萄糖基化。