methyl (5-amino-7,8,9-tri-O-acetyl-5,4-N,O-carbonyl-3,5-dideoxy-D-glycero-α-D-galacto-non-2-ulopyranoside)onate-(2->6)-(methyl 2,3,4-tri-O-benzyl-α-D-galactopyranoside) | 1235555-39-1

• 分子结构分类: 有机化合物 - 有机氧化合物
• 英文名称: methyl (5-amino-7,8,9-tri-O-acetyl-5,4-N,O-carbonyl-3,5-dideoxy-D-glycero-α-D-galacto-non-2-ulopyranoside)onate-(2->6)-(methyl 2,3,4-tri-O-benzyl-α-D-galactopyranoside)
• 英文别名: methyl (3aR,4R,6R,7aS)-6-[[(2R,3R,4S,5R,6S)-6-methoxy-3,4,5-tris(phenylmethoxy)oxan-2-yl]methoxy]-2-oxo-4-[(1S,2R)-1,2,3-triacetyloxypropyl]-3a,4,7,7a-tetrahydro-3H-pyrano[3,4-d][1,3]oxazole-6-carboxylate
• CAS: 1235555-39-1
• 化学式: C₄₅H₅₃NO₁₇
• 分子量: 879.912
• InChiKey: MRNODCYIWVHXOD-JAAPYZKRSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  3.4
• 重原子数：
  63
• 可旋转键数：
  24
• 环数：
  6.0
• sp3杂化的碳原子比例：
  0.49
• 拓扑面积：
  208
• 氢给体数：
  1
• 氢受体数：
  17

反应信息

• 作为产物：
  描述：

  甲基2,3,4-三-O-苄基-α-D-吡喃葡萄糖苷 、 methyl (7,8,9-tri-O-acetyl-5-N,4-O-carbonyl-2-thiotoluyl-3,5-dideoxy-D-glycero-β-D-galacto-non-2-lopyranoside)onate 在 N-碘代丁二酰亚胺 、 三氟甲磺酸 作用下， 以 二氯甲烷 、 乙腈 为溶剂， 反应 1.17h， 以95%的产率得到methyl (5-amino-7,8,9-tri-O-acetyl-5,4-N,O-carbonyl-3,5-dideoxy-D-glycero-α-D-galacto-non-2-ulopyranoside)onate-(2->6)-(methyl 2,3,4-tri-O-benzyl-α-D-galactopyranoside)
  参考文献：
  名称：

  5- N，4- O-羰基-7,8,9-三-O-氯乙酰基保护的唾液酸供体，用于立体选择性合成α-（2→9）-四唾液酸

  摘要：

  使用三-O-氯乙酰基衍生的唾液酸供体和三醇唾液酸受体实现了α-（2→9）-四唾液酸的有效立体选择性合成。受体和供体也都被环状5- N -4- O-羰基保护基保护。供体在原位活化条件（NIS / TfOH，-78°C，乙腈/二氯甲烷）下具有高反应活性，并且能够与各种伯，仲和叔受体进行α-选择性唾液酸化。在温和的反应条件下，容易除去反式稠合的恶唑烷酮环和O-氯乙酰基保护基，以提供完全脱保护的α（2→9）-四唾液酸。

  DOI：

  10.1021/jo100824s

文献信息

• Donor‐Reactivity‐Controlled Sialylation Reactions
  作者：Kesatebrhan Haile Asressu、Chun‐Wei Chang、Sarah Lam、Cheng‐Chung Wang

  DOI：10.1002/ejoc.202100718

  日期：2021.8.26

  AbstractAlthough tremendous efforts have been made for the efficient preparation of sialosides, controlling the stereochemical outcome of sialylation reaction still remains one of the most challenging tasks due to the unique chemical structure of sialic acid. We developed a new strategy to statistically analyze the stereoselectivity of sialylation reactions on six types of p‐tolyl thiosialosides in NIS/TfOH system using Relative Reactivity Value (RRV) as the indicator. Analysis of the reaction mechanism showed the formation of the relatively stable glycosyl bromide and glycosyl chloride intermediates from halide‐ and triflate‐containing promotors in the absence of an acceptor. We found that the α/β‐stereoselectivity, yields, and intermediate changes were associated with their donor reactivity. These findings enable to tailor the most suitable building blocks for stereo‐controlled sialylation reactions.