Methyl 4,6-O-ethylidene-β-d-galactopyranoside | 6206-66-2

• 分子结构分类: 有机化合物 - 有机杂环化合物 - 吡喃二恶英
• 英文名称: Methyl 4,6-O-ethylidene-β-d-galactopyranoside
• 英文别名: (4aR,6R,7R,8R,8aR)-6-methoxy-2-methyl-4,4a,6,7,8,8a-hexahydropyrano[3,2-d][1,3]dioxine-7,8-diol
• CAS: 6206-66-2
• 化学式: C₉H₁₆O₆
• 分子量: 220.222
• InChiKey: BSBOLIVKPWXZAN-NFRPEMGSSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  -1.2
• 重原子数：
  15
• 可旋转键数：
  1
• 环数：
  2.0
• sp3杂化的碳原子比例：
  1.0
• 拓扑面积：
  77.4
• 氢给体数：
  2
• 氢受体数：
  6

反应信息

• 作为反应物：
  描述：

  Methyl 4,6-O-ethylidene-β-d-galactopyranoside 在 吡啶 作用下， 以 1,4-二氧六环 为溶剂， 反应 108.0h， 生成 methyl 4,6-O-ethylidene-3-O-methyl-β-D-idopyranoside
  参考文献：
  名称：

  Role of the 4,6-O-acetal in the regio- and stereoselective conversion of 2,3-di-O-sulfonyl-β-d-galactopyranosides to d-idopyranosides

  摘要：

  The recently reported conversion of 2,3-di-O-sulfonyl-D-galactopyranosides to D-idopyranosides has provided an efficient route to obtaining orthogonally-protected idopyranoside building blocks with a beta-1,2-cis glycosidic linkage. In an effort to expand the scope of this process and better understand the regio- and stereoselectivity observed in the key di-inversion step of the method, a small library of 4,6-O-acetal protected galactopyranosides has been synthesized and used as substrates in the process, together with a number of substrates that lack the acetal functionality. The results suggest that although the substituent at the acetal center does not contribute to the observed selectivity of the process, the acetal group is indeed required for efficient conversion by reducing the conformational flexibility of the substrate, resulting in enhanced reaction rates at both the O-transsulfonylation and epoxide ring-opening steps. (C) 2013 Elsevier Ltd. All rights reserved.

  DOI：

  10.1016/j.carres.2013.05.001
• 作为产物：
  描述：

  乙醛 、 甲基-Β-D-吡喃半乳糖苷 在 对甲苯磺酸 作用下， 以 乙腈 为溶剂， 反应 21.0h， 以76%的产率得到Methyl 4,6-O-ethylidene-β-d-galactopyranoside
  参考文献：
  名称：

  Role of the 4,6-O-acetal in the regio- and stereoselective conversion of 2,3-di-O-sulfonyl-β-d-galactopyranosides to d-idopyranosides

  摘要：

  The recently reported conversion of 2,3-di-O-sulfonyl-D-galactopyranosides to D-idopyranosides has provided an efficient route to obtaining orthogonally-protected idopyranoside building blocks with a beta-1,2-cis glycosidic linkage. In an effort to expand the scope of this process and better understand the regio- and stereoselectivity observed in the key di-inversion step of the method, a small library of 4,6-O-acetal protected galactopyranosides has been synthesized and used as substrates in the process, together with a number of substrates that lack the acetal functionality. The results suggest that although the substituent at the acetal center does not contribute to the observed selectivity of the process, the acetal group is indeed required for efficient conversion by reducing the conformational flexibility of the substrate, resulting in enhanced reaction rates at both the O-transsulfonylation and epoxide ring-opening steps. (C) 2013 Elsevier Ltd. All rights reserved.

  DOI：

  10.1016/j.carres.2013.05.001

文献信息

• Role of the 4,6-O-acetal in the regio- and stereoselective conversion of 2,3-di-O-sulfonyl-β-d-galactopyranosides to d-idopyranosides
  作者：Rachel Hevey、Xining Chen、Chang-Chun Ling

  DOI：10.1016/j.carres.2013.05.001

  日期：2013.7

  The recently reported conversion of 2,3-di-O-sulfonyl-D-galactopyranosides to D-idopyranosides has provided an efficient route to obtaining orthogonally-protected idopyranoside building blocks with a beta-1,2-cis glycosidic linkage. In an effort to expand the scope of this process and better understand the regio- and stereoselectivity observed in the key di-inversion step of the method, a small library of 4,6-O-acetal protected galactopyranosides has been synthesized and used as substrates in the process, together with a number of substrates that lack the acetal functionality. The results suggest that although the substituent at the acetal center does not contribute to the observed selectivity of the process, the acetal group is indeed required for efficient conversion by reducing the conformational flexibility of the substrate, resulting in enhanced reaction rates at both the O-transsulfonylation and epoxide ring-opening steps. (C) 2013 Elsevier Ltd. All rights reserved.