methyl 2,3,6-tri-O-benzyl-4-O-(2-O-benzyl-3,4-O-isopropylidene-α-L-rhamnopyranosyl)-α-D-glucopyranoside | 629627-33-4

• 分子结构分类: 有机化合物 - 有机氧化合物
• 英文名称: methyl 2,3,6-tri-O-benzyl-4-O-(2-O-benzyl-3,4-O-isopropylidene-α-L-rhamnopyranosyl)-α-D-glucopyranoside
• 英文别名: (3aS,4S,6S,7R,7aR)-6-[(2R,3R,4S,5R,6S)-6-methoxy-4,5-bis(phenylmethoxy)-2-(phenylmethoxymethyl)oxan-3-yl]oxy-2,2,4-trimethyl-7-phenylmethoxy-4,6,7,7a-tetrahydro-3aH-[1,3]dioxolo[4,5-c]pyran
• CAS: 629627-33-4
• 化学式: C₄₄H₅₂O₁₀
• 分子量: 740.891
• InChiKey: UTSGDKJDPLOSSY-FYYPDGDKSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  6
• 重原子数：
  54
• 可旋转键数：
  16
• 环数：
  7.0
• sp3杂化的碳原子比例：
  0.45
• 拓扑面积：
  92.3
• 氢给体数：
  0
• 氢受体数：
  10

反应信息

• 作为反应物：
  描述：

  methyl 2,3,6-tri-O-benzyl-4-O-(2-O-benzyl-3,4-O-isopropylidene-α-L-rhamnopyranosyl)-α-D-glucopyranoside 在 溶剂黄146 作用下， 以 甲醇 、 水 为溶剂， 反应 3.0h， 以89%的产率得到methyl 2,3,6-tri-O-benzyl-4-O-(2-O-benzyl-α-L-rhamnopyranosyl)-α-D-glucopyranoside
  参考文献：
  名称：

  The 3,4-O-Carbonate Protecting Group as a β-Directing Group in Rhamnopyranosylation in Both Homogeneous and Heterogeneous Glycosylations As Compared to the Chameleon-like 2,3-O-Carbonates

  摘要：

  It is demonstrated that the beta-selectivity observed in the insoluble silver salt mediated couplings of 2,3-O-carbonate-protected rhamnosyl bromides is uniquely due to the heterogeneous nature of the reaction. In homogeneous solution these same donors are alpha-selective, a fact that is attributed to the half-chair conformation of these substances which reduces the energy barrier to oxacarbenium ion formation. It is suggested that the 2,3-O-carbonate group be dubbed torsionally arming in the manno- and rhamnopyranose series. When the carbonate group is removed to the 3,4-O-position a beta-selective system is formed, in both homogeneous and heterogeneous conditions, and it is demonstrated that this selectivity arises from the combination of the electron-withdrawing nature of the carbonate and its inability to take part in neighboring participation.

  DOI：

  10.1021/jo035003j
• 作为产物：
  描述：

  phenyl 2-O-benzyl-1-thio-β-L-rhamnopyranoside 在 1-(苯基亚硫酰基)哌啶 、 三氟甲磺酸酐 、 camphor-10-sulfonic acid 、 2,4,6-三叔丁基嘧啶 作用下， 以 四氢呋喃 、 二氯甲烷 为溶剂， 反应 17.33h， 生成 methyl 2,3,6-tri-O-benzyl-4-O-(2-O-benzyl-3,4-O-isopropylidene-α-L-rhamnopyranosyl)-α-D-glucopyranoside
  参考文献：
  名称：

  The 3,4-O-Carbonate Protecting Group as a β-Directing Group in Rhamnopyranosylation in Both Homogeneous and Heterogeneous Glycosylations As Compared to the Chameleon-like 2,3-O-Carbonates

  摘要：

  It is demonstrated that the beta-selectivity observed in the insoluble silver salt mediated couplings of 2,3-O-carbonate-protected rhamnosyl bromides is uniquely due to the heterogeneous nature of the reaction. In homogeneous solution these same donors are alpha-selective, a fact that is attributed to the half-chair conformation of these substances which reduces the energy barrier to oxacarbenium ion formation. It is suggested that the 2,3-O-carbonate group be dubbed torsionally arming in the manno- and rhamnopyranose series. When the carbonate group is removed to the 3,4-O-position a beta-selective system is formed, in both homogeneous and heterogeneous conditions, and it is demonstrated that this selectivity arises from the combination of the electron-withdrawing nature of the carbonate and its inability to take part in neighboring participation.

  DOI：

  10.1021/jo035003j

文献信息

• The 3,4-<i>O</i>-Carbonate Protecting Group as a β-Directing Group in Rhamnopyranosylation in Both Homogeneous and Heterogeneous Glycosylations As Compared to the Chameleon-like 2,3-<i>O</i>-Carbonates
  作者：David Crich、A. U. Vinod、John Picione

  DOI：10.1021/jo035003j

  日期：2003.10.1

  It is demonstrated that the beta-selectivity observed in the insoluble silver salt mediated couplings of 2,3-O-carbonate-protected rhamnosyl bromides is uniquely due to the heterogeneous nature of the reaction. In homogeneous solution these same donors are alpha-selective, a fact that is attributed to the half-chair conformation of these substances which reduces the energy barrier to oxacarbenium ion formation. It is suggested that the 2,3-O-carbonate group be dubbed torsionally arming in the manno- and rhamnopyranose series. When the carbonate group is removed to the 3,4-O-position a beta-selective system is formed, in both homogeneous and heterogeneous conditions, and it is demonstrated that this selectivity arises from the combination of the electron-withdrawing nature of the carbonate and its inability to take part in neighboring participation.