methyl 3-O-(2,3,4,6-tetra-O-acetyl-β-D-galactopyranosyl)-2-[O-(2,3,4-tri-O-acetyl-α-L-rhamnopyranosyl)acetamido]-6-O-benzyl-2-deoxy-β-D-glucopyranoside | 581797-47-9

• 分子结构分类: 有机化合物 - 有机酸及其衍生物 - 羧酸及其衍生物
• 英文名称: methyl 3-O-(2,3,4,6-tetra-O-acetyl-β-D-galactopyranosyl)-2-[O-(2,3,4-tri-O-acetyl-α-L-rhamnopyranosyl)acetamido]-6-O-benzyl-2-deoxy-β-D-glucopyranoside
• 英文别名: methyl 3-O-(2,3,4,6-tetra-O-acetyl-β-D-galactopyranosyl)-2-N-(2,3,4-tri-O-acetyl-α-L-rhamnopyranosyl)acetimido-6-O-benzyl-2-deoxy-β-D-glucopyranoside
• CAS: 581797-47-9
• 化学式: C₄₂H₅₇NO₂₂
• 分子量: 927.908
• InChiKey: BXTMQVYSHXCNMQ-KRGWMMBFSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  0.75
• 重原子数：
  65.0
• 可旋转键数：
  17.0
• 环数：
  4.0
• sp3杂化的碳原子比例：
  0.67
• 拓扑面积：
  281.3
• 氢给体数：
  1.0
• 氢受体数：
  23.0

反应信息

• 作为反应物：
  描述：

  methyl 3-O-(2,3,4,6-tetra-O-acetyl-β-D-galactopyranosyl)-2-[O-(2,3,4-tri-O-acetyl-α-L-rhamnopyranosyl)acetamido]-6-O-benzyl-2-deoxy-β-D-glucopyranoside 在 palladium on activated charcoal 4 A molecular sieve 、 氢气 、 三乙基硅基三氟甲磺酸酯 、 sodium methylate 作用下， 以 甲醇 、 二氯甲烷 为溶剂， 反应 25.0h， 生成 methyl 2-acetamido-β-D-galactopyranosyl-(1->3)-[α-L-rhamnopyranosyl-(1->4)]-2-deoxy-β-D-glucopyranoside
  参考文献：
  名称：

  The Amide Group in N-Acetylglucosamine Glycosyl Acceptors Affects Glycosylation Outcome

  摘要：

  Glycosylation of a disaccharide containing N-acetylglucosamine with rhamnosyl and mannosyl trichloracetimidates under triethysilyl triflate catalysis led to the competitive formation of glycosyl imidates. While the rhamnosyl imidate could be rearranged to the thermodynamically favored trisaccharide, the mannosyl analogue was resistant to rearrangement. Glycosylation with perbenzylated thiorhamnosides activated with methyl triflate (MeOTf) gave the trisaccharide as well as the methyl imidate trisaccharide. The less reactive alpha-thioethyl donor led to a higher relative amount of methyl imidate trisaccharide to trisaccharide than the more reactive beta-thioglycoside. When using a more reactive thioethyl fucoside only the trisaccharide was obtained. Interestingly, the acceptor treated with MeOTf gave the N-methyl imidate that could be easily rhamnosylated and subsequently converted to the N-acetamido trisaccharide. This strategy to glycosylate O-4 of N-acetylglucosamine is under further investigation. Alternatively, bis-N-acetylation of the glucosamine prevented the formation of imidates and allowed the efficient synthesis of two Lewis A trisaccharide analogues.

  DOI：

  10.1021/jo050707+
• 作为产物：
  描述：

  2,3,4-tri-O-acetyl-L-rhamnopyranosyl trichloroacetimidate 、 methyl O-(2,3,4,6-tetra-O-acetyl-β-D-galactopyranosyl)-(1<*>3)-2-acetamido-6-O-benzyl-2-deoxy-β-D-glucopyranoside 在 三乙基硅基三氟甲磺酸酯 作用下， 以 二氯甲烷 为溶剂， 以42%的产率得到methyl 3-O-(2,3,4,6-tetra-O-acetyl-β-D-galactopyranosyl)-2-[O-(2,3,4-tri-O-acetyl-α-L-rhamnopyranosyl)acetamido]-6-O-benzyl-2-deoxy-β-D-glucopyranoside
  参考文献：
  名称：

  Glycosylation of N-Acetylglucosamine:  Imidate Formation and Unexpected Conformation

  摘要：

  [GRAPHICS]Rhamnosylation in mild conditions of a disaccharide containing N-acetylglucosamine afforded the imidate 6 while at higher temperature and concentration of promoter trisaccharide 7 was isolated. The kinetic imidate 6 was independently rearranged in 50% yield to the thermodynamic trisaccharide 7. Comparative NMR studies of 7 in CDCl3 and DMSO-d(6) suggest the formation of a nonchair conformation in CDCl3. The structure of 7 was confirmed through the independent synthesis of the N-acetylacetamido trisaccharide 11.

  DOI：

  10.1021/ol034669x