(2R,3S,4R,6S)-6-(2,2-difluoroethoxy)-3,4-diethoxy-2-(ethoxymethyl)oxane | 1209486-21-4

• 分子结构分类: 有机化合物 - 有机氧化合物
• 英文名称: (2R,3S,4R,6S)-6-(2,2-difluoroethoxy)-3,4-diethoxy-2-(ethoxymethyl)oxane
• CAS: 1209486-21-4
• 化学式: C₁₄H₂₆F₂O₅
• 分子量: 312.354
• InChiKey: NKLQQNNNKLHFPL-RFHZTLPTSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  1.9
• 重原子数：
  21
• 可旋转键数：
  10
• 环数：
  1.0
• sp3杂化的碳原子比例：
  1.0
• 拓扑面积：
  46.2
• 氢给体数：
  0
• 氢受体数：
  7

反应信息

• 作为产物：
  描述：

  2,2-二氟乙醇 、 (2R,3S,4R)-3,4-diethoxy-2-(ethoxymethyl)-6-ethylsulfanyloxane 在 N-碘代丁二酰亚胺 作用下， 以 乙腈 为溶剂， 反应 1.0h， 生成 (2R,3S,4R,6S)-6-(2,2-difluoroethoxy)-3,4-diethoxy-2-(ethoxymethyl)oxane 、
  参考文献：
  名称：

  Erosion of Stereochemical Control with Increasing Nucleophilicity: O-Glycosylation at the Diffusion Limit

  摘要：

  Nucleophilic substitution reactions of 2-deoxyglycosyl donors indicated that the reactivity of the oxygen nucleophile has a significant impact on stereoselectivity. Employing ethanol as the nucleophile resulted in a 1:1 (alpha:beta) ratio of diastereomers under S(N)1-like reaction conditions. Stercoselective formation of the 2-deoxy-alpha-O-glycoside was only observed when weaker nucleophiles, such as trifluoroethanol, were employed. The lack of stercoselectivity observed in reactions of common oxygen nucleophiles can be attributed to reaction rates of the stereochemistry-determining step that approach the diffusion limit. In this scenario, both faces of the prochiral oxocarbenium ion are subject to nucleophilic addition to afford a statistical mixture of diastercomeric products. Control experiments confirmed that all nucleophilic substitution reactions were performed under kinetic control.

  DOI：

  10.1021/jo902222a

文献信息

• Erosion of Stereochemical Control with Increasing Nucleophilicity: <i>O</i>-Glycosylation at the Diffusion Limit
  作者：Matthew G. Beaver、K. A. Woerpel

  DOI：10.1021/jo902222a

  日期：2010.2.19

  Nucleophilic substitution reactions of 2-deoxyglycosyl donors indicated that the reactivity of the oxygen nucleophile has a significant impact on stereoselectivity. Employing ethanol as the nucleophile resulted in a 1:1 (alpha:beta) ratio of diastereomers under S(N)1-like reaction conditions. Stercoselective formation of the 2-deoxy-alpha-O-glycoside was only observed when weaker nucleophiles, such as trifluoroethanol, were employed. The lack of stercoselectivity observed in reactions of common oxygen nucleophiles can be attributed to reaction rates of the stereochemistry-determining step that approach the diffusion limit. In this scenario, both faces of the prochiral oxocarbenium ion are subject to nucleophilic addition to afford a statistical mixture of diastercomeric products. Control experiments confirmed that all nucleophilic substitution reactions were performed under kinetic control.