phenyl-2,3,4-tri-O-benzyl-1-thio-β-D-rhamnose | 1163254-38-3

• 分子结构分类: 有机化合物 - 有机氧化合物
• 英文名称: phenyl-2,3,4-tri-O-benzyl-1-thio-β-D-rhamnose
• CAS: 1163254-38-3
• 化学式: C₃₃H₃₄O₄S
• 分子量: 526.697
• InChiKey: WGAOZACWMVPQOY-RPZFEVNFSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  7.28
• 重原子数：
  38.0
• 可旋转键数：
  11.0
• 环数：
  5.0
• sp3杂化的碳原子比例：
  0.27
• 拓扑面积：
  36.92
• 氢给体数：
  0.0
• 氢受体数：
  5.0

反应信息

• 作为反应物：
  描述：

  phenyl-2,3,4-tri-O-benzyl-1-thio-β-D-rhamnose 、 4-methoxyphenyl 4-O-acetyl-2-O-benzyl-α-L-fucopyranoside 在 N-碘代丁二酰亚胺 、 三氟甲磺酸三甲基硅酯 作用下， 以 二氯甲烷 为溶剂， 反应 1.5h， 以89%的产率得到4-methoxyphenyl (2,3,4-tri-O-benzyl-α-D-rhamnopyranosyl)-(1→3)-4-O-acetyl-2-O-benzyl-α-L-fucopyranoside
  参考文献：
  名称：

  巴西固氮螺旋藻SR80细胞壁脂多糖重复单元的简捷合成

  摘要：

  摘要 在连续的糖基化策略之后，已经以良好的产率实现了巴西固氮螺旋藻SR80的细胞壁脂多糖的三糖和四糖重复单元作为其4-甲氧基苯基（PMP）糖苷的合成。所有中间步骤都是高产率的，糖基化步骤是高度立体选择性的。 在连续的糖基化策略之后，已经以良好的产率实现了巴西固氮螺旋藻SR80的细胞壁脂多糖的三糖和四糖重复单元作为其4-甲氧基苯基（PMP）糖苷的合成。所有中间步骤都是高产率的，糖基化步骤是高度立体选择性的。

  DOI：

  10.1055/s-0033-1341256
• 作为产物：
  描述：

  在 lithium aluminium tetrahydride 作用下， 以 四氢呋喃 为溶剂， 以0.66 g的产率得到phenyl-2,3,4-tri-O-benzyl-1-thio-β-D-rhamnose
  参考文献：
  名称：

  Stereodirecting Effect of the Pyranosyl C-5 Substituent in Glycosylation Reactions

  摘要：

  The stereodirecting effect of the glycosyl C-5 substituent has been investigated in a series of D-pyranosyl thioglycoside donors and related to their preferred positions in the intermediate H-3(4) and H-4(3) half-chair oxacarbenium ions. Computational studies showed that an axially positioned C-5 carboxylate ester can stabilize the (3)H4 half-chair oxacarbenium ion conformer by donating electron densit from its carbonyl function into the electron-poor oxacarbenium ion functionality. A similar stabilization can be achieved by a C-5 benzyloxyrnethyl group, but,the magnitude of this stabilization is significantly smaller than for the C-5 carboxylate ester. As a result, the preference of the C-5 benzyloxymethyl to occupy an axial position in the half-chair oxacarbenium ions is much reduced compared to the C-5 carboxylate ester. To minimize steric interactions, a C-5 methyl group prefers to adopt an equatorial position and therefore favors the H-4(3) half-chair oxacarbenium ion. When all pyranosyl substituents occupy their favored position in one of the two intermediate half-chair oxacarbenium ions, highly stereoselective glycosylations can be achieved as revealed by the excellent beta-selectivity of mannuronate esters and alpha-selectivity of 6-deoxygulosides.

  DOI：

  10.1021/jo900662v