(E)-3-Methoxy-4-hexene | 202072-77-3

• 分子结构分类: 有机化合物 - 有机氧化合物
• 英文名称: (E)-3-Methoxy-4-hexene
• 英文别名: (E,4R)-4-methoxyhex-2-ene
• CAS: 202072-77-3
• 化学式: C₇H₁₄O
• 分子量: 114.188
• InChiKey: DOMBBEHJVXKOID-PTYLAXBQSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  1.9
• 重原子数：
  8
• 可旋转键数：
  3
• 环数：
  0.0
• sp3杂化的碳原子比例：
  0.71
• 拓扑面积：
  9.2
• 氢给体数：
  0
• 氢受体数：
  1

反应信息

• 作为反应物：
  描述：

  (E)-3-Methoxy-4-hexene 在 二甲基硫 、 臭氧 作用下， 生成 (R)-2-Methoxy-butyraldehyde
  参考文献：
  名称：

  Conformational study of chiral alkenes: the influence of protective groups on the relative stability of ground-state rotational isomers

  摘要：

  A variable temperature NMR study shows that a protective group on the hydroxy function of a chiral allylic alcohol can either enhance or counter the influence of the vinyl substituent on the ground-state (GS) conformations. If the allylic hydroxy is protected as a methyl ether, the CH-eclipsed form I becomes favored to a greater degree for normal chiral alkenes. Furthermore, conformer I becomes preferred even for the gamma-hydroxy-alpha,beta-unsaturated esters, which normally favor the CO-eclipsed form (II). On the other hand, the tert-butyldimethylsilyl (TBDMS) ether enhances the preference for conformer II for the gamma-hydroxy-alpha,beta-unsaturated esters and diminishes the preference for the CH-eclipsed form of normal chiral alkenes. These facts are explained by the size of the allylic oxygen lone pairs.

  DOI：

  10.1021/jo00077a023
• 作为产物：
  描述：

  ((E)-(S)-1-Ethyl-but-2-enyl)-methyl-oxonium 40.0 ℃ 、95.99 kPa 条件下， 生成 2-methoxy-hex-3t-ene 、 (E)-3-Methoxy-4-hexene
  参考文献：
  名称：

  Intracomplex CH₃OH Walking around Optically Active 1-Methyl-3-ethylallyl Cations. A Gas-Phase Kinetic Study

  摘要：

  The kinetics and the mechanism of the racemization and regioisomerization of O-methylated (S)-trans-4-hexen-3-ol (IS') or (R)-trans-3-hexen-2-ol (IIR') have been investigated in the gas phase at 720 Torr and in the 40-120 degrees C temperature range. The starting oxonium intermediates were generated in the gas phase by the reaction of (CH3)(2)Cl+ ions, formed by stationary gamma-radiolysis of bulk CH3Cl, on the corresponding optically active alcohols. The rate constant of the gas-phase regioisomerization of IS' ((3.4-16.0) x 10(6) s(-1)) was found to exceed that of its racemization ((1.9-9.8) x 10(6) s(-1)) over the entire temperature range. Similar differences were observed for the regioisomerization ((2.9-15.0) x 10(6) s(-1)) and the racemization of IIR' ((1.8-9.6) x 10(6) s(-1)). By analogy with previous experimental and theoretical evidence, these results are consistent with intramolecular racemization and regioisomerization processes involving the intermediacy of two distinct hydrogen-bonded complexes, wherein the CH3OH molecule is coplanarly coordinated to the in-plane hydrogens of the 1-methyl-3-ethylallyl moiety. The activation parameters for their formation from the IS' and IIR' were evaluated and compared with those concerning the racemization and regioisomerization of O-protonated (S)-trans-4-hexen-3-ol (IS), previously measured in the gas phase under similar experimental conditions. The comparison reveals that gas-phase racemization and regioisomerization of O-protonated (S)-trans-4-hexen-3-ol (1S') (AOH=H2O) involve transition structures located early along the reaction coordinate, whereas the transition structures involved in the rearrangement of O-methylated (S)-trans-4-hexen-3-ol (1S') and (R)-trans-3-hexen-2-ol (IIR') (AOH = CH3OH) are placed later along the reaction coordinate and are characterized by a strong coordination of the moving CH3OH molecule with the hydrogens of the allylic moiety.

  DOI：

  10.1021/jo971282x

文献信息

• Intracomplex CH₃OH Walking around Optically Active 1-Methyl-3-ethylallyl Cations. A Gas-Phase Kinetic Study
  作者：Anna Troiani、Maurizio Speranza

  DOI：10.1021/jo971282x

  日期：1998.2.1

  The kinetics and the mechanism of the racemization and regioisomerization of O-methylated (S)-trans-4-hexen-3-ol (IS') or (R)-trans-3-hexen-2-ol (IIR') have been investigated in the gas phase at 720 Torr and in the 40-120 degrees C temperature range. The starting oxonium intermediates were generated in the gas phase by the reaction of (CH3)(2)Cl+ ions, formed by stationary gamma-radiolysis of bulk CH3Cl, on the corresponding optically active alcohols. The rate constant of the gas-phase regioisomerization of IS' ((3.4-16.0) x 10(6) s(-1)) was found to exceed that of its racemization ((1.9-9.8) x 10(6) s(-1)) over the entire temperature range. Similar differences were observed for the regioisomerization ((2.9-15.0) x 10(6) s(-1)) and the racemization of IIR' ((1.8-9.6) x 10(6) s(-1)). By analogy with previous experimental and theoretical evidence, these results are consistent with intramolecular racemization and regioisomerization processes involving the intermediacy of two distinct hydrogen-bonded complexes, wherein the CH3OH molecule is coplanarly coordinated to the in-plane hydrogens of the 1-methyl-3-ethylallyl moiety. The activation parameters for their formation from the IS' and IIR' were evaluated and compared with those concerning the racemization and regioisomerization of O-protonated (S)-trans-4-hexen-3-ol (IS), previously measured in the gas phase under similar experimental conditions. The comparison reveals that gas-phase racemization and regioisomerization of O-protonated (S)-trans-4-hexen-3-ol (1S') (AOH=H2O) involve transition structures located early along the reaction coordinate, whereas the transition structures involved in the rearrangement of O-methylated (S)-trans-4-hexen-3-ol (1S') and (R)-trans-3-hexen-2-ol (IIR') (AOH = CH3OH) are placed later along the reaction coordinate and are characterized by a strong coordination of the moving CH3OH molecule with the hydrogens of the allylic moiety.
• Conformational study of chiral alkenes: the influence of protective groups on the relative stability of ground-state rotational isomers
  作者：Benjamin W. Gung、Mark A. Wolf

  DOI：10.1021/jo00077a023

  日期：1993.12

  A variable temperature NMR study shows that a protective group on the hydroxy function of a chiral allylic alcohol can either enhance or counter the influence of the vinyl substituent on the ground-state (GS) conformations. If the allylic hydroxy is protected as a methyl ether, the CH-eclipsed form I becomes favored to a greater degree for normal chiral alkenes. Furthermore, conformer I becomes preferred even for the gamma-hydroxy-alpha,beta-unsaturated esters, which normally favor the CO-eclipsed form (II). On the other hand, the tert-butyldimethylsilyl (TBDMS) ether enhances the preference for conformer II for the gamma-hydroxy-alpha,beta-unsaturated esters and diminishes the preference for the CH-eclipsed form of normal chiral alkenes. These facts are explained by the size of the allylic oxygen lone pairs.