2-endo-(4-methoxyphenyl)-2-exo-hydro-5-methylbicylo<3.2.1>octane-6,8-dione | 79135-51-6

• 分子结构分类: 有机化合物 - 苯类化合物 - 苯酚醚
• 英文名称: 2-endo-(4-methoxyphenyl)-2-exo-hydro-5-methylbicylo<3.2.1>octane-6,8-dione
• 英文别名: (1R,2R,5R)-2-(4-methoxyphenyl)-5-methylbicyclo[3.2.1]octane-6,8-dione
• CAS: 79135-51-6
• 化学式: C₁₆H₁₈O₃
• 分子量: 258.317
• InChiKey: GCVJKJHGWUHKMR-WOSRLPQWSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  2.4
• 重原子数：
  19
• 可旋转键数：
  2
• 环数：
  3.0
• sp3杂化的碳原子比例：
  0.5
• 拓扑面积：
  43.4
• 氢给体数：
  0
• 氢受体数：
  3

反应信息

• 作为产物：
  描述：

  2-甲基-1,3-环戊二酮 在 palladium on activated charcoal 氢气 、 对甲苯磺酸 、 三乙胺 作用下， 以 乙醚 、 乙醇 、 苯 为溶剂， 反应 34.0h， 生成 2-endo-(4-methoxyphenyl)-2-exo-hydro-5-methylbicylo<3.2.1>octane-6,8-dione
  参考文献：
  名称：

  1H and13C NMR spectral studies of C-2 substituted isomericexo- andendo-5-methyl-bicyclo[3.2.1]octane-6,8-diones

  摘要：

  AbstractA detailed analysis of the 1H and 13C NMR spectra of C‐2 aryl and alkyl/desalkyl substituted isomeric exo‐ and endo‐5‐methylbicyclo[3.2.1]octane‐6,8‐diones is presented. The chemical shift of the C‐5 angular methyl, the C‐2 alkyl/olefinic (C‐10)/C‐2 methine protons, the aromatic proton shieldings and the characteristic AMX and ABX spectral pattern of the ketomethylene and bridgehead protons were found to be sensitive to the phenyl ring orientation (anisotropy). These distinctive features could be used for configurational distinction for this class of compounds. With increasing ortho‐methoxy substitution on the phenyl ring, considerable deshilelding of the bridgehead proton was observed (ca. 0.6 ppm). Absence of the C‐2 alkyl group in the desalkyl isomers resulted in substantial changes in the chemical shifts of different protons. A study of the NMR spectra of the corresponding bicyclic compounds with C‐2 methoxy/hydroxy substitution instead of the aryl group revealed that the anisotropy of the phenyl ring and the electronegative oxygen substituents have opposite effects.The 13C NMR spectral assignment of each carbon resonance of C‐2 aryl and alkyl/desalkyl substituted isomeric exo‐ and endo‐5‐methylbicyclo[3.2.1]octane‐6,8‐diones and the corresponding C‐2 methoxy/hydroxy/chloro and methyl bicyclic compounds are reported. Additional ortho‐methoxy substitution on the phenyl ring was found to produce considerable high field shifts of the C‐10 and C‐1 carbon resonances. A high‐field shift was observed for the C‐6 and C‐8 carbonyl carbons, presumably due to 1,3‐dicarbonyl interactions. The chemical shifts of C‐1′ aromatic, C‐10 alkyl and C‐2 carbons, which are sensitive to exo/endo isomerism, could be utilized in differentiating a pair of isomers.

  DOI：

  10.1002/mrc.1270200112

文献信息

• Isomeric bicyclo[3,2,1]octane-6,8-diones: nuclear magnetic resonance as a probe for stereochemical distinction
  作者：Tirumalai R. Kasturi、Parvathi S. Murthy、S. Madhava Reddy、Mohan M. Bhadbhade、Kailasam Venkatesan

  DOI：10.1021/jo00337a040

  日期：1981.11