(2S,3R,3aS,9aS)-3-(1-bromoethenyl)-5,5,7,7-tetraisopropyl-2-methoxy-1,4,6,8-tetraoxa-5,7-disilabicyclo[6.3.0]undecan-3-ol

• 分子结构分类: 有机化合物 - 有机氧化合物
• 英文名称: (2S,3R,3aS,9aS)-3-(1-bromoethenyl)-5,5,7,7-tetraisopropyl-2-methoxy-1,4,6,8-tetraoxa-5,7-disilabicyclo[6.3.0]undecan-3-ol
• 英文别名: (6aS,8S,9R,9aS)-9-(1-bromoethenyl)-8-methoxy-2,2,4,4-tetra(propan-2-yl)-6,6a,8,9a-tetrahydrofuro[3,2-f][1,3,5,2,4]trioxadisilocin-9-ol
• 化学式: C₂₀H₃₉BrO₆Si₂
• 分子量: 511.601
• InChiKey: VQFGKHQNSDQSDN-LWYYNNOASA-N

计算性质

• 辛醇/水分配系数(LogP)：
  4.95
• 重原子数：
  29
• 可旋转键数：
  6
• 环数：
  2.0
• sp3杂化的碳原子比例：
  0.9
• 拓扑面积：
  66.4
• 氢给体数：
  1
• 氢受体数：
  6

反应信息

• 作为产物：
  描述：

  、 溴乙烯 在 正丁基锂 、 lithium bromide 、 三甲基氯硅烷 作用下， 以 四氢呋喃 、 乙醚 、 正戊烷 为溶剂， 反应 0.5h， 生成 (2S,3R,3aS,9aS)-3-(1-bromoethenyl)-5,5,7,7-tetraisopropyl-2-methoxy-1,4,6,8-tetraoxa-5,7-disilabicyclo[6.3.0]undecan-3-ol 、 (2S,3S,3aS,9aS)-3-(1-bromoethenyl)-5,5,7,7-tetraisopropyl-2-methoxy-1,4,6,8-tetraoxa-5,7-disilabicyclo[6.3.0]undecan-3-ol
  参考文献：
  名称：

  1-Bromo-1-lithioethene:  A Practical Reagent in Organic Synthesis

  摘要：

  A reliable preparative scale synthesis of 1-bromo-1-lithioethene is reported. This reagent undergoes clean 1,2-addition with a range of aldehydes and ketones at -110 degrees C to afford the corresponding 2-bromo-1-alken-3-ols in moderate to excellent yield. Trapping with other electrophiles (acylsilanes, chlorosilanes, tributyltin chloride, iodine) cleanly provides practically useful yields of various 1-substituted 1-bromoethene products. Unexpectedly high diastereoselectivities were observed during the addition of 1-bromo-1-lithioethene to alpha-siloxy aldehydes (typically 10:1, Felkin-Ahn control) and protected ketopyranose and ketofuranose sugars (>= 10:1, addition from the less-hindered face). The title organolithium reagent possesses relatively low basicity at low temperature, and is compatible with a variety of common protecting groups. We believe that these unusual properties of 1-bronio-1-lithioethene may originate from the specific crystalline structure of the reagent in which lithium is coordinatively saturated and thus unavailable for chelation.

  DOI：

  10.1021/jo051125v