ethyl 2,3,4-tri-O-benzyl-1-thio-β-L-rhamnopyranosyde | 136758-06-0

• 分子结构分类: 有机化合物 - 有机氧化合物
• 英文名称: ethyl 2,3,4-tri-O-benzyl-1-thio-β-L-rhamnopyranosyde
• 英文别名: ethyl 2,3,4-tri-O-benzyl-1-thio-β-L-rhamnopyranoside；(2R,3R,4R,5S,6S)-2-ethylsulfanyl-6-methyl-3,4,5-tris(phenylmethoxy)oxane
• CAS: 136758-06-0
• 化学式: C₂₉H₃₄O₄S
• 分子量: 478.653
• InChiKey: RZVKVTBAQRMTEH-UMUOWMJJSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  5.7
• 重原子数：
  34
• 可旋转键数：
  11
• 环数：
  4.0
• sp3杂化的碳原子比例：
  0.38
• 拓扑面积：
  62.2
• 氢给体数：
  0
• 氢受体数：
  5

反应信息

• 作为反应物：
  描述：

  ethyl 2,3,4-tri-O-benzyl-1-thio-β-L-rhamnopyranosyde 在 4 A molecular sieve 、 乙酸酐 、 溶剂黄146 、 三氟甲烷磺酸甲酯 作用下， 以 乙醚 为溶剂， 反应 21.0h， 生成 methyl 2-acetamido-3-O-(2,3,4,6-tetra-O-acetyl-β-D-galactopyranosyl)-6-O-benzyl-4-O-(2,3,4-tri-O-benzyl-α-L-rhamnopyranosyl)-2-deoxy-α-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：

  溴甲苯 、 ethyl 1-thio-β-L-rhamnopyranoside 在 sodium hydride 作用下， 以 N,N-二甲基甲酰胺 、 mineral oil 为溶剂， 反应 2.0h， 以89%的产率得到ethyl 2,3,4-tri-O-benzyl-1-thio-β-L-rhamnopyranosyde
  参考文献：
  名称：

  Effect of Remote Picolinyl and Picoloyl Substituents on the Stereoselectivity of Chemical Glycosylation

  摘要：

  O-Picolinyl and O-picoloyl groups at remote positions (C-3, C-4, and C-6) can mediate glycosylation reactions by providing high or even complete facial selectivity for the attack of the glycosyl acceptor. The set of data presented herein offers a strong evidence of the intermolecular H-bond tethering between the glycosyl donor and glycosyl acceptor counterparts while providing a practical new methodology for the synthesis of either 1,2-cis or 1,2-trans linkages. Challenging glycosidic linkages including alpha-gluco, beta-manno, and beta-rhamno have seen obtained with high or complete stereocontrol.

  DOI：

  10.1021/ja307355n

文献信息

• Synthesis of a group of diosgenyl saponins with combined use of glycosyl trichloroacetimidate and thioglycoside donors
  作者：Hai Yu、Biao Yu、Xiangyang Wu、Yongzheng Hui、Xiuwen Han

  DOI：10.1039/a909218h

  日期：——

  With the combined use of glycosyl trichloroacetimidates and thioglycosides, a group of natural diosgenyl saponins (1–6) are efficiently synthesized, in either a stepwise or a ‘one-pot’ manner. The trichloroacetimidate is employed as an efficient temporary hydroxy protecting group in glycosylation with the glycosyl trichloroacetimidate. The intermolecular alkylthio-group transfer is demonstrated to be a common side-reaction during glycosylation with thioglycosides.

  通过结合使用糖基三氯乙亚胺酯和硫代糖苷，一系列天然薯蓣皂苷元的皂苷（1-6）被高效地合成，无论是逐步合成还是“一锅法”合成。三氯乙亚胺酯作为糖基化反应中糖基三氯乙亚胺酯的临时羟基保护组，表现出高效性。硫代糖苷参与的糖基化反应中，分子的烷硫基转移被证实是一种常见的副反应。
• Convenient Temporary Methyl Imidate Protection of <i>N</i>-Acetylglucosamine and Glycosylation at O-4
  作者：Anderson Cheng、Jenifer L. Hendel、Kimberley Colangelo、Michael Bonin、France-Isabelle Auzanneau

  DOI：10.1021/jo801117y

  日期：2008.10.3

  reactions, the 3-O-acylated methyl and ethyl imidates of glucosamine were shown to behave well during the glycosylation of the 4-OH with a variety of reaction conditions and various glycosyl donors. Glycosylation of these acceptors was successfully carried out with perbenzylated beta-thioethyl rhamnopyranoside under MeOTf promotion, while activation of this donor under NIS/TMSOTf or NIS/TfOH proved less

  当尝试在N-乙酰氨基葡萄糖受体的O-4处糖基化时，本文扩展了N-乙酰基暂时转化为烷基酰亚胺的范围和用途。描述了在位置4并在O-3处带有各种保护基的亚氨酸烷基酯保护的葡糖胺受体的优化合成。通过用0.5M MeOTf处理4-OH受体，立即在糖基化之前制备这些酰亚胺，以获得仍带有游离4-OH基团的相应的甲基酰亚胺。当在作为反应溶剂的乙醚中制备这些酰亚胺时，我们观察到除了所需的甲基酰亚胺外，还会出乎意料地形成乙基酰亚胺。尽管3-O-烯丙基受体非常不稳定，无法用于糖基化反应，在各种反应条件和各种糖基供体的作用下，在4-OH的糖基化过程中，葡糖胺的3-O-酰化的甲基和乙基酰亚胺被证明表现良好。这些受体的糖基化是在MeOTf促进下用过苄基的β-硫代乙基鼠李吡喃糖苷成功进行的，而在NIS / TMSOTf或NIS / TfOH下激活该供体则证明不太成功。相反，用NIS / TfOH活化反应性较低的全苄基化
• Synthesis of disaccharide methyl glycosides related to the polysaccharide from Klebsiella serotype 40 and a study of their inhibition in the precipitin reaction
  作者：Usha B. Maddali、Asim K. Ray、Nirmolendu Roy

  DOI：10.1016/0008-6215(90)80085-h

  日期：1990.12

  Galp (4), beta-L-Rhap-(1----3)-beta-D-Galp (5), beta-D-Galp-(1----2)-alpha-L-Rhap (6), and beta-D-GlcpA-(1----2)-alpha-L-Rhap (7) have been synthesised and their inhibition reactions in the Klebsiella serotype 40 immune system have been studied. The results obtained accord with only one of two structures proposed for the repeating unit of the K40 antigen.

  alpha-D-Manp-（1 ---- 4）-alpha-L-Rhap（3），alpha-L-Rhap-（1 ---- 3）-beta-D-Galp（4 ），beta-L-Rhap-（1 ---- 3）-beta-D-Galp（5），beta-D-Galp-（1 ---- 2）-alpha-L-Rhap（6），合成了β-D-GlcpA-（1 ---- 2）-α-L-Rhap（7）并研究了它们在克雷伯菌血清型40免疫系统中的抑制反应。获得的结果仅与为K40抗原的重复单位提出的两个结构之一一致。