(3aS,8bR)-3a-Ethyl-6,8b-dimethyl-3-oxo-2,3,3a,8b-tetrahydro-1H-benzo[b]cyclopenta[d]furan-2-carboxylic acid ethyl ester | 138629-71-7

• 分子结构分类: 有机化合物 - 有机杂环化合物 - 内酯类
• 英文名称: (3aS,8bR)-3a-Ethyl-6,8b-dimethyl-3-oxo-2,3,3a,8b-tetrahydro-1H-benzo[b]cyclopenta[d]furan-2-carboxylic acid ethyl ester
• CAS: 138629-71-7
• 化学式: C₁₈H₂₂O₄
• 分子量: 302.37
• InChiKey: PLSMIOVLTMZBGF-VIYFESSGSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  2.95
• 重原子数：
  22.0
• 可旋转键数：
  3.0
• 环数：
  3.0
• sp3杂化的碳原子比例：
  0.56
• 拓扑面积：
  52.6
• 氢给体数：
  0.0
• 氢受体数：
  4.0

反应信息

• 作为反应物：
  描述：

  (3aS,8bR)-3a-Ethyl-6,8b-dimethyl-3-oxo-2,3,3a,8b-tetrahydro-1H-benzo[b]cyclopenta[d]furan-2-carboxylic acid ethyl ester 在 二甲基亚砜 、 lithium chloride 作用下， 以 水 为溶剂， 生成 cis-3-oxo-1,2,3a,8b-tetrahydro-3a-ethyl-6,8b-dimethyl-3H-cyclopentabenzofuran
  参考文献：
  名称：

  Rapid, high-yield synthesis of the marine sesquiterpenes debromoaplysin and aplysin via the acid-catalyzed rearrangement of a cyclobutachromanol

  摘要：

  A short, stereocontrolled, high-yield synthesis of debromoaplysin (1) and aplysin (2) from the chromone 13 is described. The cycloaddition of ethylene to 13, followed by the addition of methylmagnesium iodide to the cycloadduct, furnished the cyclobutachromanol 15. Treatment of 15 in benzene with BF3.Et2O furnished a mixture of the alkenes 16 and 17, which can be visualized as arising by way of the initial 1,2-migration of the external and internal bonds, respectively, of the cyclobutane ring of 15. Similar rearrangement of 18, an ethyl analogue of 15, yielded 19 and 20. Rearrangement of 15 on treatment with sulfuric acid in petroleum ether at -78-degrees-C furnished, almost exclusively, 17. In contrast, when performed in nitroethane at -78-degrees-C, the same reaction afforded 16 exclusively. Thus, the solvent exerted a remarkable effect on the outcome of the rearrangement. Since alkene 16 had previously been converted to 1 and 2, this work represents an improved synthesis of the two sesquiterpenes.

  DOI：

  10.1021/jo00031a026
• 作为产物：
  描述：

  重氮乙酸乙酯 、 cis-2a,7b-dihydro-2a-ethyl-5,7b-dimethylcyclobutabenzofuran-2(1H)-one 在 三氟化硼乙醚 作用下， 生成 (3aS,8bR)-3a-Ethyl-6,8b-dimethyl-3-oxo-2,3,3a,8b-tetrahydro-1H-benzo[b]cyclopenta[d]furan-2-carboxylic acid ethyl ester
  参考文献：
  名称：

  Rapid, high-yield synthesis of the marine sesquiterpenes debromoaplysin and aplysin via the acid-catalyzed rearrangement of a cyclobutachromanol

  摘要：

  A short, stereocontrolled, high-yield synthesis of debromoaplysin (1) and aplysin (2) from the chromone 13 is described. The cycloaddition of ethylene to 13, followed by the addition of methylmagnesium iodide to the cycloadduct, furnished the cyclobutachromanol 15. Treatment of 15 in benzene with BF3.Et2O furnished a mixture of the alkenes 16 and 17, which can be visualized as arising by way of the initial 1,2-migration of the external and internal bonds, respectively, of the cyclobutane ring of 15. Similar rearrangement of 18, an ethyl analogue of 15, yielded 19 and 20. Rearrangement of 15 on treatment with sulfuric acid in petroleum ether at -78-degrees-C furnished, almost exclusively, 17. In contrast, when performed in nitroethane at -78-degrees-C, the same reaction afforded 16 exclusively. Thus, the solvent exerted a remarkable effect on the outcome of the rearrangement. Since alkene 16 had previously been converted to 1 and 2, this work represents an improved synthesis of the two sesquiterpenes.

  DOI：

  10.1021/jo00031a026