trans-7-(4-Chlorophenyl)-2,3-dicarbomethoxy-7-phenylbicyclo<2.2.1>hepta-2,5-diene | 143680-29-9

• 分子结构分类: 有机化合物 - 苯丙烷和聚酮
• 英文名称: trans-7-(4-Chlorophenyl)-2,3-dicarbomethoxy-7-phenylbicyclo<2.2.1>hepta-2,5-diene
• CAS: 143680-29-9
• 化学式: C₂₃H₁₉ClO₄
• 分子量: 394.854
• InChiKey: BGXGGDRRLAWVPW-FEJSZKPUSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  4.08
• 重原子数：
  28.0
• 可旋转键数：
  4.0
• 环数：
  4.0
• sp3杂化的碳原子比例：
  0.22
• 拓扑面积：
  52.6
• 氢给体数：
  0.0
• 氢受体数：
  4.0

反应信息

• 作为产物：
  描述：

  2-(4-chlorophenyl)-2-phenylcyclopent-4-enone 在 sodium tetrahydroborate 、 cerium(III) chloride 、 对甲苯磺酸 作用下， 以 甲醇 、 苯 为溶剂， 反应 18.67h， 生成 trans-7-(4-Chlorophenyl)-2,3-dicarbomethoxy-7-phenylbicyclo<2.2.1>hepta-2,5-diene
  参考文献：
  名称：

  Stereoelectronic control of facial selectivity in the Diels-Alder cycloaddition of sterically unbiased 5,5-diarylcyclopentadienes

  摘要：

  This study provides strong evidence for stereoelectronic control of diastereoselectivity in the Diels-Alder cycloaddition of sterically unbiased 5-(4-X-phenyl)-5-phenylcyclopentadienes 1 (X = NO2, Cl, and N(CH3)2) with dimethyl acetylenedicarboxylate (DMAD) producing diastereomeric norbornyl diesters 2 in cis/trans ratios (diester relative to the substituted arene) varying from 68:32 to 38:62 as determined by IH NMR spectroscopy. The reactions were carried out under both thermal and Lewis acid catalyzed conditions, giving essentially identical selectivities regardless of the conditions used. Structural assignments were made by H-1 NMR lanthanide shift reagent studies of the isolated diastereomers, separable by preparative thin-layer chromatography. In each case the dienophile approached the diene from the side opposite the more electron rich aromatic ring as predicted by Cieplak's theory for explaining stereoelectronic control. The observed ratios correspond to an overall energy difference of 0.65 kcal/mol. A Hammet plot of the log (cis/trans) versus the sigma(p) parameter produced a linear relationship with a correlation coefficient of 0.98. An efficient synthesis of the diarylcyclopentadienes is described.

  DOI：

  10.1021/jo00047a009