Ethyl 4-O-acetyl-2,3-di-O-benzoyl-1-thio-α-L-rhamnopyranoside | 172361-27-2

• 分子结构分类: 有机化合物 - 有机氧化合物
• 英文名称: Ethyl 4-O-acetyl-2,3-di-O-benzoyl-1-thio-α-L-rhamnopyranoside
• 英文别名: [(2S,3R,4R,5S,6S)-5-acetyloxy-3-benzoyloxy-2-ethylsulfanyl-6-methyloxan-4-yl] benzoate
• CAS: 172361-27-2
• 化学式: C₂₄H₂₆O₇S
• 分子量: 458.532
• InChiKey: JXJLNVSFODQPMG-YARBZOEJSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  4.7
• 重原子数：
  32
• 可旋转键数：
  10
• 环数：
  3.0
• sp3杂化的碳原子比例：
  0.38
• 拓扑面积：
  113
• 氢给体数：
  0
• 氢受体数：
  8

反应信息

• 作为反应物：
  描述：

  Ethyl 4-O-acetyl-2,3-di-O-benzoyl-1-thio-α-L-rhamnopyranoside 在 吡啶 、 4-二甲氨基吡啶 、 N-碘代丁二酰亚胺 、 三氟甲磺酸 、 4 A molecular sieve 、 碘 作用下， 以 甲醇 为溶剂， 反应 8.17h， 生成 Bz(-2)[Bz(-3)]Rha4Ac(a1-3)[Bz(-2)][Bz(-4)][Bz(-6)]Gal(b)-O-EtTMS
  参考文献：
  名称：

  Synthesis of a Pentasaccharide Epitope for the Investigation of Carbohydrate-Protein Interactions

  摘要：

  Pyranose residues of a polysaccharide that are not involved in the principal sugar-protein antibody combining site, filled by trisaccharide 1, cause a 50-fold reduction in intrinsic affinity. The antibody is crystallographically characterized, and the residue responsible for the lost binding energy has been identified as the terminal disaccharide Rha-->Gal of pentasaccharide 5. This disaccharide segment of 5 may avoid protein contact by adopting the ''anti'' conformer about the preceding Man-Rha glycosidic linkage. Monosaccharide thioglycoside synthons 6-9 were used in NIS-promoted glycosylations to synthesize the pentasaccharide as a glycoside that was suitable for binding and solution conformational studies. Disaccharide 29 was obtained upon the addition of rhamnose building unit 6 to the (trimethylsilyl)ethyl galactopyranoside 10 followed by protecting group manipulation. The sequential addition of 7-9 to 29 afforded the pentasaccharide derivative 35 bearing a 2-O-benzoate group suited for subsequent 1,2-trans-glycoside synthesis following its conversion to a glycosyl imidate. In order to preserve the integrity of the 3,6-dideoxyhexopyranosyl glycosidic bond during cleavage of the (trimethylsilyl)ethyl group leading to the imidate 39, it was essential to convert the benzylated pentasaccharide target 35 into its fully acylated derivative 37. Pentasaccharide 5 was obtained by transesterification of the protected glycoside 40 formed via 39. Qualitative NOE measurements suggest a predominant solution conformation for 5 that cannot be adopted in the bound state due to protein-oligosaccharide clashes at the periphery of the binding site.

  DOI：

  10.1021/jo00127a043
• 作为产物：
  描述：

  ethyl 4-O-acetyl-2,3-O-isopropylidene-1-thio-α-L-rhamnopyranoside 在 吡啶 、 溶剂黄146 作用下， 反应 4.0h， 生成 Ethyl 4-O-acetyl-2,3-di-O-benzoyl-1-thio-α-L-rhamnopyranoside
  参考文献：
  名称：

  Synthesis of a Pentasaccharide Epitope for the Investigation of Carbohydrate-Protein Interactions

  摘要：

  Pyranose residues of a polysaccharide that are not involved in the principal sugar-protein antibody combining site, filled by trisaccharide 1, cause a 50-fold reduction in intrinsic affinity. The antibody is crystallographically characterized, and the residue responsible for the lost binding energy has been identified as the terminal disaccharide Rha-->Gal of pentasaccharide 5. This disaccharide segment of 5 may avoid protein contact by adopting the ''anti'' conformer about the preceding Man-Rha glycosidic linkage. Monosaccharide thioglycoside synthons 6-9 were used in NIS-promoted glycosylations to synthesize the pentasaccharide as a glycoside that was suitable for binding and solution conformational studies. Disaccharide 29 was obtained upon the addition of rhamnose building unit 6 to the (trimethylsilyl)ethyl galactopyranoside 10 followed by protecting group manipulation. The sequential addition of 7-9 to 29 afforded the pentasaccharide derivative 35 bearing a 2-O-benzoate group suited for subsequent 1,2-trans-glycoside synthesis following its conversion to a glycosyl imidate. In order to preserve the integrity of the 3,6-dideoxyhexopyranosyl glycosidic bond during cleavage of the (trimethylsilyl)ethyl group leading to the imidate 39, it was essential to convert the benzylated pentasaccharide target 35 into its fully acylated derivative 37. Pentasaccharide 5 was obtained by transesterification of the protected glycoside 40 formed via 39. Qualitative NOE measurements suggest a predominant solution conformation for 5 that cannot be adopted in the bound state due to protein-oligosaccharide clashes at the periphery of the binding site.

  DOI：

  10.1021/jo00127a043