反应详情

Into a four-necked flask equipped with a stirrer and a thermometer, 5% sulfuric acid (10 ml) was charged, and dl-3-acetoxy-2-allyl-3-methyl-4-cyclopentenone (2 g) was dropwise added thereto in 1 hour while keeping the inner temperature at 30° to 50° C. After completion of the dropwise addition, the resultant mixture was kept at the same temperature as above for 3 hours. Thereafter, sodium chloride (3 g) was added to the reaction mixture, which was extracted with methyl isobutyl ketone (20 ml) three times. The organic layer was washed with a saturated aqueous sodium chloride solution, and methyl isobutyl ketone was removed by distillation. The residue was purified by column chromatography to give 1.27 g of 2-allyl-4-hydroxy-3-methyl-2-cyclopentenone. Yield, 84%.

1. customInto a four-necked flask equipped with a stirrer
2. additionwas dropwise added
3. customat 30° to 50° C
4. additionAfter completion of the dropwise addition
5. customwas kept at the same temperature as above for 3 hours
6. extractionwas extracted with methyl isobutyl ketone (20 ml) three times
7. washThe organic layer was washed with a saturated aqueous sodium chloride solution, and methyl isobutyl ketone
8. customwas removed by distillation
9. customThe residue was purified by column chromatography