3-butyl-3-ethoxy-6-methoxycyclohexene

• 分子结构分类: 有机化合物 - 有机氧化合物
• 英文名称: 3-butyl-3-ethoxy-6-methoxycyclohexene
• 化学式: C₁₃H₂₄O₂
• 分子量: 212.332
• InChiKey: UOHHMOOEPFMBJC-UHFFFAOYSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  2.9
• 重原子数：
  15
• 可旋转键数：
  6
• 环数：
  1.0
• sp3杂化的碳原子比例：
  0.85
• 拓扑面积：
  18.5
• 氢给体数：
  0
• 氢受体数：
  2

反应信息

• 作为产物：
  描述：

  4-羟基环己酮乙二醇缩醛 在 potassium tert-butylate 、 pyridinium hydrobromide perbromide 、 草酸 、 silica gel 、 sodium hydride 作用下， 以 四氢呋喃 、 乙醚 、 正己烷 、 二氯甲烷 、 二甲基亚砜 为溶剂， 反应 7.5h， 生成 3-butyl-3-ethoxy-6-methoxycyclohexene
  参考文献：
  名称：

  Stereospecific Retro-Diels-Alder fragmentation of stereoisomeric 3-methoxy- and 3,6-dialkoxytricyclo[6.2.2.02,7]dodeca-9-enes upon electron ionization

  摘要：

  The stereoisomeric 2,3-cis- and 2,3-trans-3-methoxytricyclo[6.2.2.0(2,7)]dodeca-9-enes endo-1 and exo-1 (endo and exo refer to the methoxy group) exhibit different behavior under electron ionization (EI): the m/z 80 cyclohexa-1,3-diene radical cation formed by retro-Diels-Alder (RDA) fragmentation is the most abundant ion in the 70 eV mass spectrum of endo-1, whereas exo-1 exhibits preferential formation of an m/z 111 ion corresponding to the O-methylcyclohex-2-en-1-one structure (ion a), which may be obtained by an RDA fragmentation accompanied by a hydrogen migration (RDA - H), with the charge retained in the dienophile moiety. A similar effect has been observed in the EI mass spectra of the four stereoisomeric 3-ethoxy-6-methoxytricyclo [6.2.2.0(2,7)] dodeca-9-enes 2; endo-2, with both endo-alkoxy groups, gives rise to the most abundant mit 80 ion via the regular RDA process, whereas the other three stereoisomers, with at least one exo-alkoxy group, afford the most abundant m/z 155 ions via the RDA -H process, which correspond to the 4-alkoxy-substituted analogues of the mit 111 ion a obtained from exo-1. Collision-induced dissociation measurements and a deuterium labeling study showed that che mit 155 ions obtained from the two trans-diethers (trans-2a and trans-2b) have isomeric structures b and c (a mixture of b and c is formed in the case of exo-2), and that the highly stereospecific RDA -H process involves a double hydrogen transfer, one from position 4 to the diene moiety and the other from position 3 to 4. The above stereospecific behavior shows that the thermodynamically favored RDA -H process has a higher activation energy than the regular RDA fragmentation in the case of endo-1 and endo-2. In all other isomers, which have at least one exo-alkoxyl, the activation energy of the KDA -H process is lower than that of RDA. The latter effect is ascribed to anchimeric assistance of the alkoxyl in the initial C-C bond cleavage in the stepwise RDA -H process, which is possible only when at least one alkoxyl has the exo configuration. (C) 1998 John Wiley & Sons, Ltd.

  DOI：

  10.1002/(sici)1096-9888(199803)33:3<229::aid-jms632>3.0.co;2-b

文献信息

• Stereospecific Retro-Diels-Alder fragmentation of stereoisomeric 3-methoxy- and 3,6-dialkoxytricyclo[6.2.2.02,7]dodeca-9-enes upon electron ionization
  作者：N. Morlender-Vais、A. Mandelbaum

  DOI：10.1002/(sici)1096-9888(199803)33:3<229::aid-jms632>3.0.co;2-b

  日期：1998.3

  The stereoisomeric 2,3-cis- and 2,3-trans-3-methoxytricyclo[6.2.2.0(2,7)]dodeca-9-enes endo-1 and exo-1 (endo and exo refer to the methoxy group) exhibit different behavior under electron ionization (EI): the m/z 80 cyclohexa-1,3-diene radical cation formed by retro-Diels-Alder (RDA) fragmentation is the most abundant ion in the 70 eV mass spectrum of endo-1, whereas exo-1 exhibits preferential formation of an m/z 111 ion corresponding to the O-methylcyclohex-2-en-1-one structure (ion a), which may be obtained by an RDA fragmentation accompanied by a hydrogen migration (RDA - H), with the charge retained in the dienophile moiety. A similar effect has been observed in the EI mass spectra of the four stereoisomeric 3-ethoxy-6-methoxytricyclo [6.2.2.0(2,7)] dodeca-9-enes 2; endo-2, with both endo-alkoxy groups, gives rise to the most abundant mit 80 ion via the regular RDA process, whereas the other three stereoisomers, with at least one exo-alkoxy group, afford the most abundant m/z 155 ions via the RDA -H process, which correspond to the 4-alkoxy-substituted analogues of the mit 111 ion a obtained from exo-1. Collision-induced dissociation measurements and a deuterium labeling study showed that che mit 155 ions obtained from the two trans-diethers (trans-2a and trans-2b) have isomeric structures b and c (a mixture of b and c is formed in the case of exo-2), and that the highly stereospecific RDA -H process involves a double hydrogen transfer, one from position 4 to the diene moiety and the other from position 3 to 4. The above stereospecific behavior shows that the thermodynamically favored RDA -H process has a higher activation energy than the regular RDA fragmentation in the case of endo-1 and endo-2. In all other isomers, which have at least one exo-alkoxyl, the activation energy of the KDA -H process is lower than that of RDA. The latter effect is ascribed to anchimeric assistance of the alkoxyl in the initial C-C bond cleavage in the stepwise RDA -H process, which is possible only when at least one alkoxyl has the exo configuration. (C) 1998 John Wiley & Sons, Ltd.