反应详情

温度

25 °C

To 32.5 g (0.19 mol) of 2-n-pentyl-1,3-cyclopentanedione was added 650 ml of methanol containing 1 wt % of hydrogen chloride (prepared by preliminarily blowing hydrogen chloride therein), followed by heating under reflux for 5 hours and cooling to 25° C. Then, thereto was gradually added 15.4 g of sodium hydrogencarbonate followed by stirring for 30 minutes at 25° C. Methanol was distilled off in vacuo and then 200 mL of water and 200 mL of isobutanol were added. The resulting mixture was stirred for 10 minutes at 25° C. and then allowed to stand to separate the organic phase. Isobutanol in the organic phase was distilled off, yielding 2-pentyl-3-methoxy-2-cyclopentenone (a compound in which R20 represents an n-pentyl group, and R21 represents a methyl group in the above formula (14)). Gas chromatographic analysis showed that the yield of 2-pentyl-3-methoxy-2-cyclopentenone relative to 2-n-pentyl-1,3-cyclopentanedione was 80%.

1. temperatureby heating
2. temperatureunder reflux for 5 hours
3. distillationMethanol was distilled off in vacuo
4. addition200 mL of water and 200 mL of isobutanol were added
5. stirringThe resulting mixture was stirred for 10 minutes at 25° C.
6. customto separate the organic phase
7. distillationIsobutanol in the organic phase was distilled off