Sulfuric Acid → 2-Cyclopenten-1-one, 4-hydroxy-3-methyl-2-(2-propen-1-yl)-
Reaction equation
C(O[C:5]1([CH3:14])[CH:9]=[CH:8][C:7](=[O:10])[CH:6]1[CH2:11][CH:12]=[CH2:13])(=O)C.[Cl-].[Na+].S(=O)(=O)(O)[OH:18]>>[CH2:11]([C:6]1[C:7](=[O:10])[CH2:8][CH:9]([OH:18])[C:5]=1[CH3:14])[CH:12]=[CH2:13]Participants
Procedure
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%.
Workup
- customInto a four-necked flask equipped with a stirrer
- additionwas dropwise added
- customat 30° to 50° C
- additionAfter completion of the dropwise addition
- customwas kept at the same temperature as above for 3 hours
- extractionwas extracted with methyl isobutyl ketone (20 ml) three times
- washThe organic layer was washed with a saturated aqueous sodium chloride solution, and methyl isobutyl ketone
- customwas removed by distillation
- customThe residue was purified by column chromatography
Sources & evidence
- ORD record
- ord-d1804938b4ce4d208732c92aa0d9b893
- Source dataset
- uspto-grants-1986_08
- Patent number
- US04608442
Reaction notes
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