反应详情

A buffer solution was prepared by dissolving sodium acetate (1.03 g) and MgCl2.6H2O (0.27 g) in water (200 ml) and adjusting the pH value to 6.0 (20° C.) with acetic acid. In a reaction vessel, 5-methyl-2-furylallylcarbinol (5 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 3 hours. After ice-cooling, sodium chloride (50 g) was added, and the mixture was extracted with methyl isobutyl ketone (100 ml) four times. The extract was concentrated at 60° C. under reduced pressure to remove methyl isobutyl ketone, whereby an oily substance (4.6 g) was obtained. The crude product was purified by column chromatography with silica gel (60 g) (developing solvent, ethyl acetate-n-hexane (1:2 by volume)) to obtain 2-allyl-3-methyl-4-hydroxy-2-cyclopentenone (4.0 g). Yield, 80%.

1. customA buffer solution was prepared
2. customto 6.0 (20° C.)
3. additionabove were charged
4. stirringThe mixture was stirred at the same temperature for 3 hours
5. temperatureAfter ice-cooling
6. extractionthe mixture was extracted with methyl isobutyl ketone (100 ml) four times
7. concentrationThe extract was concentrated at 60° C. under reduced pressure
8. customto remove methyl isobutyl ketone, whereby an oily substance (4.6 g)
9. customwas obtained
10. customThe crude product was purified by column chromatography with silica gel (60 g) (developing solvent, ethyl acetate-n-hexane (1:2 by volume))