反应详情

Potassium secondary phosphate (1.12 g) and potassium primary phosphate (3.54 g) were dissolved in water (800 ml) to prepare a buffer solution (pH 6.2, 20° C.). In a reaction vessel, 5-methyl-2-furylallylcarbinol (20 g) and the entire amount of the buffer solution as prepared above were charged, and the temperature was elevated up to 150° C. in 35 minutes while stirring. The mixture was stirred at the same temperature for 4 hours, the inner pressure at this time being 3.8 kg/cm2. After cooling with ice, sodium chloride (100 g) was added thereto, and the mixture was extracted with methyl isobutyl ketone (200 ml) four times. The extract was concentrated at 60° C. under reduced pressure to remove methyl isobutyl ketone, whereby an oily substance (18.2 g) was obtained. The crude product was purified by distillation (130°-132° C./1.2 mmHg) to obtain 2-allyl-3-methyl-4-hydroxy-2-cyclopentenone (16.6 g). Yield, 83%.

1. customto prepare a buffer solution (pH 6.2, 20° C.)
2. additionabove were charged
3. stirringThe mixture was stirred at the same temperature for 4 hours
4. additionwas added
5. extractionthe mixture was extracted with methyl isobutyl ketone (200 ml) four times
6. concentrationThe extract was concentrated at 60° C. under reduced pressure
7. customto remove methyl isobutyl ketone, whereby an oily substance (18.2 g)
8. customwas obtained
9. distillationThe crude product was purified by distillation (130°-132° C./1.2 mmHg)