Isopropanol → Propan-2-yl 4-methyl-3-oxopentanoate
Reaktionsgleichung
[CH3:1][CH:2]([CH3:10])[C:3](=[O:9])[CH2:4][C:5](OC)=[O:6].C1(C)C=CC(S(O)(=O)=O)=CC=1.[CH:22]([OH:25])([CH3:24])[CH3:23]>>[CH3:1][CH:2]([CH3:10])[C:3](=[O:9])[CH2:4][C:5]([O:25][CH:22]([CH3:24])[CH3:23])=[O:6]Komponenten
4
Reaktionsbedingungen
- Temperatur
- 90 °C
Versuchsvorschrift
Methyl 4-methyl-3-oxo-pentanoate (304 g), isopropyl alcohol (500 ml) and p-toluenesulfonic acid (3.8 g) were stirred together and heated to reflux at 90° C. After 3 hours, 400 ml of solvent was collected by distillation at atmospheric pressure. Fresh isopropyl alcohol was added and the mixture refluxed for a further 3 hours. The cycle of distillation, addition of fresh solvent and refluxing was continued until the conversion had reached 95%, determined by a peak area ratio of product:starting material of 95:5 measured by LC. The remaining volatile solvents were removed by distillation and the resultant liquid washed with 10% sodium carbonate solution and dried over anhydrous sodium sulfate and filtered to give isopropyl 4-methyl-3-oxo-pentanoate as a clear liquid (301 g, 83%).