Methyl-isobutenyl-hydroxy-carboniumion | 19760-33-9

• 分子结构分类: 有机化合物 - 有机氧化合物
• 英文名称: Methyl-isobutenyl-hydroxy-carboniumion
• 英文别名: (Z)-4-methyl-pent-3-en-2-one; protonated form
• CAS: 19760-33-9
• 化学式: C₆H₁₁O
• 分子量: 99.1527
• InChiKey: IBBUQZAAEGGPTL-UHFFFAOYSA-N

反应信息

• 作为产物：
  描述：

  4-甲基-3戊烯-2-酮 在 硫酸 作用下， 生成 Methyl-isobutenyl-hydroxy-carboniumion 、 、
  参考文献：
  名称：

  Carbodications. 3. The two dications derived from mesityl oxide

  摘要：

  The hydronation of mesityl oxide (4) is best followed by measuring the difference between chemical shifts of signals for C(4) and C(3) (DELTA-delta), linearly extrapolated at infinite dilution. It was found that half-hydronation occurs near H0-4. The acidity dependence of C(4) and DELTA-delta-0 indicates, however, that the amount of positive charge increases monotonically in stronger acids (100% H2SO4, CF3SO3H, 4:1 FSO3H-SbF5), far beyond the acidity level where hydronation should be complete. The existence of a fast second hydronation of 4 is proposed; the same conclusion comes from a study of acidity dependence of the slope of the DELTA-delta vs concentration of 4 line. The fast second hydronation forms a dication with two hydrons attached to oxygen. The other dication, hydronated at C(3) and at oxygen, is the intermediate in conversions of 4 in superacid. Its rate of formation is estimated from the exchange of C(3)-H in FSO3D-SbF5 to an extent of 60% in 20 min at 30-degrees-C. Even though the second hydronation at C(3) is slow, the rate-determining step for the conversion of 4 occurs after it.

  DOI：

  10.1021/jo00021a017