(1S,4S,5S)-5-Ethynyl-bicyclo[2.2.1]hept-2-en-7-one

• 分子结构分类: 有机化合物 - 有机氧化合物
• 英文名称: (1S,4S,5S)-5-Ethynyl-bicyclo[2.2.1]hept-2-en-7-one
• 英文别名: (1S,4S,5S)-5-ethynylbicyclo[2.2.1]hept-2-en-7-one
• 化学式: C₉H₈O
• 分子量: 132.162
• InChiKey: QMCBTHOEBVBHSI-RNJXMRFFSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  1
• 重原子数：
  10
• 可旋转键数：
  0
• 环数：
  2.0
• sp3杂化的碳原子比例：
  0.44
• 拓扑面积：
  17.1
• 氢给体数：
  0
• 氢受体数：
  1

反应信息

• 作为反应物：
  描述：

  (1S,4S,5S)-5-Ethynyl-bicyclo[2.2.1]hept-2-en-7-one 在 sodium tetrahydroborate 作用下， 生成 (1S,4S,5S,7S)-5-Ethynyl-bicyclo[2.2.1]hept-2-en-7-ol 、 (1S,4S,5S,7R)-5-Ethynyl-bicyclo[2.2.1]hept-2-en-7-ol
  参考文献：
  名称：

  A simple computational model for predicting .pi.-facial selectivity in reductions of sterically unbiased ketones. Relative importance of electrostatic and orbital interactions

  摘要：

  Various factors controlling the preferred facial selectivity in the reductions of a number of sterically unbiased ketones have been evaluated using a semiempirical MO procedure. MNDO optimized geometries do not reveal any significant ground-state distortions which can be correlated with the observed face selectivities. Electrostatic effects due to an approaching reagent were modeled by placing a test negative charge at a fixed distance from the carbonyl carbon on each of the two faces. A second series of calculations was carried out using the hydride ion as a test nucleophile. The latter calculations effectively include orbital interactions involving the sigma and sigma* orbitals of the newly formed bond in the reaction. The computed energy differences with the charge model are generally much larger compared to those with the hydride ion. However, both models lead to predictions which are qualitatively consistent with the experimentally determined facial preferences for most of the systems. Thus, electrostatic interactions between the nucleophile and the substrate seem to effectively determine the face selectivities in these molecules. However, there are a few exceptions in which orbital interactions are found to contribute significantly and occasionally reverse the preference dictated by electrostatic effects. The remarkable success of the hydride model calculations, in spite of retaining the unperturbed geometries of the substrates, points to the unimportance of torsional effects and orbital distortions associated with the pyramidalized carbonyl unit in the transition state in most of the substrates considered. Additional experimental results are reported which provide useful calibration for the present computational approach.

  DOI：

  10.1021/jo00059a022

文献信息

• A simple computational model for predicting .pi.-facial selectivity in reductions of sterically unbiased ketones. Relative importance of electrostatic and orbital interactions
  作者：Bishwajit Ganguly、Jayaraman Chandrasekhar、Faiz Ahmed Khan、Goverdhan Mehta

  DOI：10.1021/jo00059a022

  日期：1993.3

  Various factors controlling the preferred facial selectivity in the reductions of a number of sterically unbiased ketones have been evaluated using a semiempirical MO procedure. MNDO optimized geometries do not reveal any significant ground-state distortions which can be correlated with the observed face selectivities. Electrostatic effects due to an approaching reagent were modeled by placing a test negative charge at a fixed distance from the carbonyl carbon on each of the two faces. A second series of calculations was carried out using the hydride ion as a test nucleophile. The latter calculations effectively include orbital interactions involving the sigma and sigma* orbitals of the newly formed bond in the reaction. The computed energy differences with the charge model are generally much larger compared to those with the hydride ion. However, both models lead to predictions which are qualitatively consistent with the experimentally determined facial preferences for most of the systems. Thus, electrostatic interactions between the nucleophile and the substrate seem to effectively determine the face selectivities in these molecules. However, there are a few exceptions in which orbital interactions are found to contribute significantly and occasionally reverse the preference dictated by electrostatic effects. The remarkable success of the hydride model calculations, in spite of retaining the unperturbed geometries of the substrates, points to the unimportance of torsional effects and orbital distortions associated with the pyramidalized carbonyl unit in the transition state in most of the substrates considered. Additional experimental results are reported which provide useful calibration for the present computational approach.