3-ethyl-β-pinene | 150296-70-1

• 分子结构分类: 有机化合物 - 脂质和类脂质分子 - 异戊烯醇脂质
• 英文名称: 3-ethyl-β-pinene
• CAS: 150296-70-1
• 化学式: C₁₂H₂₀
• 分子量: 164.291
• InChiKey: QNJYCRVRFQHCLX-FHZGLPGMSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  3.63
• 重原子数：
  12.0
• 可旋转键数：
  1.0
• 环数：
  3.0
• sp3杂化的碳原子比例：
  0.83
• 拓扑面积：
  0.0
• 氢给体数：
  0.0
• 氢受体数：
  0.0

反应信息

• 作为产物：
  描述：

  (+)-α-蒎烯 、 碘乙烷 在 正丁基锂 、 potassium tert-butylate 作用下， 生成 (+)-2-n-Propylapopinene 、 3-ethyl-β-pinene
  参考文献：
  名称：

  Selective reductions. 46. Effect of the steric requirement at the 2-position of apopinene on chiral reductions. B-(iso-2-ethylapopinocampheyl)- and B-(iso-2-n-propylapopinocampheyl)-9-borabicyclo[3.3.1]nonanes as improved reagents for the chiral reduction of .alpha.,.beta.-acetylenic ketones and .alpha.-keto esters

  摘要：

  B-(Iso-2-ethylapopinocampheyl)-9-borabicyclo[3.3.1]nonane (Eapine-Borane, 7), and B-(Iso-2-n-propylapopinocampheyl)-9-borabicyclo[3.3.1]nonane (Prapine-Borane, 9), prepared via the hydroboration of 2-ethylapopinene (6) or 2-n-propylapopinene (8), respectively, with 9-borabicyclo[3.3.1]nonane, reduce prochiral alpha,beta-acetylenic ketones and alpha-keto esters to the corresponding alcohols with significantly higher optical induction than does Alpine-Borane (1). (-)-2-n-Propylapopinene was synthesized by treating nopyl tosylate with dimethyl cuprate prepared in situ from ethyllithium and cuprous iodide. (+)-2-n-Propylapopinene was synthesized by Schlosser metalation of (+)-alpha-pinene followed by treatment with ethyl iodide. 4-Phenyl-3-butyn-2-one was reduced to the corresponding propargylic alcohol in 89% ee and 96% ee by Eapine-Borane and Prapine-Borane, respectively, as compared to 82% ee with Alpine-Borane. Similar improved results were realized in the reduction of other acetylenic ketones by Eapine-Borane and Prapine-Borane. Similar improvements in the optical yields were realized in the reduction of alpha-keto esters by Eapine-Borane. For example, while Alpine-Borane produced methyl and ethyl lactate in 92% and 91% ee, respectively, Eapine-Borane gave these alcohols in 97% and 96% ee, respectively. Unfortunately, Prapine-Borane shows no improvement in percent ee for the reduction of alpha-keto esters. The increase in the percent ee realized is tentatively attributed to the increased steric requirements of the alkyl group at the 2-position of apopinene.

  DOI：

  10.1021/jo00313a020