4-chlorophenyl (5-acetamido-3,5-dideoxy-D-glycero-β-D-galacto-non-2-ulopyranosylonic acid) | 856173-90-5

• 分子结构分类: 有机化合物 - 有机氧化合物
• 英文名称: 4-chlorophenyl (5-acetamido-3,5-dideoxy-D-glycero-β-D-galacto-non-2-ulopyranosylonic acid)
• 英文别名: 4-chlorophenyl β-D-sialoside；NeuAc(b)-O-Ph(4-Cl)；(2R,4S,5R,6R)-5-acetamido-2-(4-chlorophenoxy)-4-hydroxy-6-[(1R,2R)-1,2,3-trihydroxypropyl]oxane-2-carboxylic acid
• CAS: 856173-90-5
• 化学式: C₁₇H₂₂ClNO₉
• 分子量: 419.816
• InChiKey: HXCJNKJRTGNVIL-CXECBNLGSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  -0.5
• 重原子数：
  28
• 可旋转键数：
  7
• 环数：
  2.0
• sp3杂化的碳原子比例：
  0.53
• 拓扑面积：
  166
• 氢给体数：
  6
• 氢受体数：
  9

反应信息

• 作为产物：
  描述：

  methyl [4-chlorophenyl(5-acetamido-4,7,8,9-tetra-O-acetyl-3,5-dideoxy-D-glycero-β-D-galacto-non-2-ulopyranosyl)]onate 在 lithium hydroxide 、 sodium methylate 作用下， 以 四氢呋喃 、 甲醇 为溶剂， 反应 0.5h， 生成 4-chlorophenyl (5-acetamido-3,5-dideoxy-D-glycero-β-D-galacto-non-2-ulopyranosylonic acid)
  参考文献：
  名称：

  Unexpected Stability of Aryl β-N-Acetylneuraminides in Neutral Solution:  Biological Implications for Sialyl Transfer Reactions

  摘要：

  A reagent panel comprised of seven aryl beta-D-N-acetylneuraminides was synthesized and then used to probe the mechanisms of nonenzymatic hydrolysis. These reactions proceeded via four independent pathways: (1) acid-catalyzed hydrolysis of the neutral molecule; (2) acid-catalyzed hydrolysis of the anionic form, or its kinetic equivalent spontaneous hydrolysis of the neutral form; (3) spontaneous hydrolysis of the anionic form; and (4) a base-promoted pathway. The pH-independent spontaneous hydrolysis of 4-nitrophenyl alpha-D-N-acetylneuraminide (5) occurs at a rate that is over 100 times faster than that of the corresponding reaction of 4-nitrophenyl O-D-N-acetylneuraminide (4a). Spontaneous hydrolyses of four aryl beta-D-N-acetylneuraminides displayed a beta(lg) value of -1.24 +/- 0.16 (pH = 8.1, T= 100 degrees C), and at a pH value of 1.0 (50 degrees C), all seven panel members gave a beta(lg) value of 0.14 +/- 0.08. The aqueous ethanolyses of 4a and 5 gave similar products and displayed sensitivity parameters (m) in a standard Winstein-Grunwald analysis of -0.04 +/- 0.01 and +0.23 +/- 0.02, respectively. These results, plus the activation parameters calculated for the spontaneous hydrolyses of the anionic forms of 5 (Delta H = 116 +/- 2 U mol(-1) and Delta S = 27 +/- 4 J mol(-1) K-1) and 4a (Delta H = 138 3 U mol(-1) and AS = 59 +/- 8 J mol(-1) K-1), are inconsistent with anomeric carboxylate assistance occurring during the hydrolysis reactions, and the likely cause for the enhanced reactivity of 5 in comparison to that of 4a is an increase in ground-state steric strain.

  DOI：

  10.1021/ja042280e