phenyl 4-O-benzyl-2,3-O-carbonyl-1-thio-α-L-rhamnopyranoside | 535961-57-0

• 分子结构分类: 有机化合物 - 有机氧化合物
• 英文名称: phenyl 4-O-benzyl-2,3-O-carbonyl-1-thio-α-L-rhamnopyranoside
• 英文别名: (3aR,4S,6S,7S,7aR)-6-methyl-7-phenylmethoxy-4-phenylsulfanyl-4,6,7,7a-tetrahydro-3aH-[1,3]dioxolo[4,5-c]pyran-2-one
• CAS: 535961-57-0
• 化学式: C₂₀H₂₀O₅S
• 分子量: 372.442
• InChiKey: BJIMBJKYGGHRSU-QZCFVMSDSA-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 4-O-benzyl-2,3-O-carbonyl-1-thio-α-L-rhamnopyranoside 在 溴 作用下， 以 二氯甲烷 为溶剂， 反应 1.0h， 生成 4-O-benzyl-2,3-O-carbonyl-α-L-rhamnopyranosyl bromide
  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 4-O-benzyl-1-thio-α-L-rhamnopyranoside 在 吡啶 作用下， 以 甲苯 为溶剂， 反应 2.0h， 生成 phenyl 4-O-benzyl-2,3-O-carbonyl-1-thio-α-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

• Ph₂SO/Tf₂O:  a Powerful Promotor System in Chemoselective Glycosylations Using Thioglycosides
  作者：Jeroen D. C. Codée、Remy E. J. N. Litjens、René den Heeten、Herman S. Overkleeft、Jacques H. van Boom、Gijs A. van der Marel

  DOI：10.1021/ol034312t

  日期：2003.5.1

  [GRAPHICS]Diphenylsulfoxide in combination with triflic anhydride provides a very potent thiophilic glycosylation promotor system, capable of activating disarmed thioglycosides. The usefulness of this novel thiophilic activator is illustrated in a successful chemoselective glycosylation sequence in which the donor thioglycoside in the first condensation step may be either armed or disarmed.