cholesteryl 3,4,6-tri-O-Ac-2-O-(2,3,4-tri-O-Bn-α-L-rhamnopyranosyl)-D-glucopyranoside | 129796-74-3

• 分子结构分类: 有机化合物 - 脂质和类脂质分子 - 类固醇和类固醇衍生物
• 英文名称: cholesteryl 3,4,6-tri-O-Ac-2-O-(2,3,4-tri-O-Bn-α-L-rhamnopyranosyl)-D-glucopyranoside
• CAS: 129796-74-3
• 化学式: C₆₆H₉₀O₁₃
• 分子量: 1091.43
• InChiKey: OLHBNKZFQMKXKT-GGHUWHHJSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  12.45
• 重原子数：
  79.0
• 可旋转键数：
  22.0
• 环数：
  9.0
• sp3杂化的碳原子比例：
  0.65
• 拓扑面积：
  143.51
• 氢给体数：
  0.0
• 氢受体数：
  13.0

反应信息

• 作为产物：
  描述：

  2,3,4-tri-O-benzyl-α-L-rhamnopyranosyl chloride 、 cholesteryl 3,4,6-tri-O-acetyl-β-D-gluco-pyranoside 反应 0.75h， 以74%的产率得到cholesteryl 3,4,6-tri-O-Ac-2-O-(2,3,4-tri-O-Bn-α-L-rhamnopyranosyl)-D-glucopyranoside
  参考文献：
  名称：

  α-Selective thermal glycosidation of rhamnosyl and mannosyl chlorides

  摘要：

  DOI：

  10.1016/s0040-4039(00)97381-7

文献信息

• β-Selective Glycosylation Using Axial-Rich and 2-<i>O</i>-Rhamnosylated Glucosyl Donors Controlled by the Protecting Pattern of the Second Sugar
  作者：Masafumi Bando、Yuri Kawasaki、Osamu Nagata、Yasunori Okada、Daiki Ikuta、Kazutada Ikeuchi、Hidetoshi Yamada

  DOI：10.1248/cpb.c20-00733

  日期：2021.1.1

  Herein, we describe two counterexamples of the previously reported β/α-selectivity of 96/4 for glycosylation using ethyl 2-O-[2,3,4-tris-O-tert-butyldimethylsilyl (TBS)-α-L-rhamnopyranosyl]-3,4,6-tris-O-TBS-thio-β-D-glucopyranoside as the glycosyl donor. Furthermore, we investigated the effects of protecting group on the rhamnose moieties in the glycosylation with cholestanol and revealed that β-selectivity originated from the two TBS groups at the 3-O and 4-O positions of rhamnose. In contrast, the TBS group at the 2-O position of rhamnose hampered the β-selectivity. Finally, the β/α-selectivity during the glycosylation was enhanced to ≥99/1. The results obtained herein suggest that the protecting groups on the sugar connected to the 2-O of a glycosyl donor with axial-rich conformation can control the stereoselectivity of glycosylation.

  本文描述了先前报道的β/α-选择性为96/4的两个反例，使用乙基2-O-[2,3,4-三-O-叔丁基二甲基硅基(TBS)-α-L-鼠李糖吡喃糖苷]-3,4,6-三-O-TBS-硫代-β-D-葡萄糖吡喃糖苷作为糖基供体进行糖基化。此外，我们研究了胆固醇醇糖基化中鼠李糖部分保护基的影响，并揭示了β-选择性源于鼠李糖的3-O和4-O位置上的两个TBS基团。相比之下，鼠李糖2-O位置上的TBS基团阻碍了β-选择性。最终，糖基化过程中的β/α-选择性提高至≥99/1。本文获得的结果表明，与轴向富集构象的糖基供体的2-O相连的糖上的保护基可以控制糖基化的立体选择性。