phenyl 2-O-benzyl-3,4-O-carbonyl-1-thio-β-L-rhamnopyranoside | 629627-27-6

• 分子结构分类: 有机化合物 - 有机氧化合物
• 英文名称: phenyl 2-O-benzyl-3,4-O-carbonyl-1-thio-β-L-rhamnopyranoside
• 英文别名: (3aS,4S,6R,7R,7aR)-4-methyl-7-phenylmethoxy-6-phenylsulfanyl-4,6,7,7a-tetrahydro-3aH-[1,3]dioxolo[4,5-c]pyran-2-one
• CAS: 629627-27-6
• 化学式: C₂₀H₂₀O₅S
• 分子量: 372.442
• InChiKey: IIVMTIJSJAERHG-RKWNZTQVSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  4.3
• 重原子数：
  26
• 可旋转键数：
  5
• 环数：
  4.0
• sp3杂化的碳原子比例：
  0.35
• 拓扑面积：
  79.3
• 氢给体数：
  0
• 氢受体数：
  6

反应信息

• 作为反应物：
  描述：

  phenyl 2-O-benzyl-3,4-O-carbonyl-1-thio-β-L-rhamnopyranoside 在 溴 、 silver carbonate 作用下， 以 二氯甲烷 为溶剂， 反应 15.0h， 生成 3β-cholestanyl 2-O-benzyl-3,4-O-carbonyl-β-L-rhamnopyranoside
  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：

  光气 、 phenyl 2-O-benzyl-1-thio-β-L-rhamnopyranoside 在 4-二甲氨基吡啶 作用下， 以 二氯甲烷 、 甲苯 为溶剂， 反应 0.5h， 以81%的产率得到phenyl 2-O-benzyl-3,4-O-carbonyl-1-thio-β-L-rhamnopyranoside
  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

• Stereocontrolled Formation of β-Glucosides and Related Linkages in the Absence of Neighboring Group Participation:  Influence of a <i>trans</i>-Fused 2,3-<i>O</i>-Carbonate Group
  作者：David Crich、Prasanna Jayalath

  DOI：10.1021/jo0508999

  日期：2005.9.1

  [GRAPHICS]Phenyl 4,6-di-O-benzyl-2,3-O-carbonyl-beta-D-glucothiopyranoside and the regiosiomeric phenyl 2,6-di-O-benzyl-3,4-O-carbonyl-beta-D-glucothiopyranoside were prepared and studied as glucosyl donors at -60 degrees C in dichloromethane with preactivation by 1-benzenesulfinyl piperidine before addition of the acceptor alcohol. The 2,3-O-carbonate protected donor showed moderate to excellent beta-selectivity under these conditions depending on the acceptor employed, thereby providing a means for 1,2-trans-equatorial glycosidic bonds without recourse to neighboring group participation and its associated problem of ortho ester formation. In contrast, the 3,4-O-carbonate protected donor showed moderate to no beta-selectivity under the conditions employed. The results obtained in this study with carbonate protected glucopyranosyl donors are contrasted with those obtained previously in the manno- and rhamnopyranosyl series when the 2,3-O-carbonate protected is (x-selective and the 3,4-O-carbonate is beta-selective.
• On the nitrile effect in l-rhamnopyranosylation
  作者：David Crich、Mitesh Patel

  DOI：10.1016/j.carres.2006.03.036

  日期：2006.7

  It is shown that the use of 5% acetonitrile or propionitrile in dichloromethane functions to increase the beta-selectivity of a number of L-rhamnopyranosylation reactions conducted by the thioglycoside method with activation by the 1-benzenesulfinyl piperidine/trifluoromethanesulfonic anhydride couple. The use of more significant quantities of acetonitrile or propionitrile results in the formation of complex reaction mixtures containing little coupled product, but from which Ritter-type products can be isolated. (c) 2006 Elsevier Ltd. All rights reserved.
• 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.