Acetic Anhydride → 4-Oxo-5-pentylcyclopent-2-en-1-yl acetate

HRID 568764Notes

Reaction equation

HRID 568764 reaction equation
[OH:1][CH:2]1[CH:6]=[CH:5][C:4](=[O:7])[CH:3]1[CH2:8][CH2:9][CH2:10][CH2:11][CH3:12].[C:13](OC(=O)C)(=[O:15])[CH3:14]>C1(C)C=CC(S(O)(=O)=O)=CC=1>[C:13]([O:7][CH:4]1[CH:5]=[CH:6][C:2](=[O:1])[CH:3]1[CH2:8][CH2:9][CH2:10][CH2:11][CH3:12])(=[O:15])[CH3:14]

Participants

4

Reactant 2

HCID 7918Acetic Anhydride2×HCID 131761314-Hydroxy-5-pentylcyclopent-2-en-1-one

Product 1

HCID 140974914-Oxo-5-pentylcyclopent-2-en-1-yl acetateYield 92.9%

Reagents, catalysts & solvents 1

HCID 6101p-Toluenesulfonic acidCatalyst

Procedure

Into a flask equipped with a stirrer and a thermometer, dl-3-hydroxy-2-n-pentyl-4-cyclopentenone (16.8 g), p-toluenesulfonic acid (0.1 g) and acetic anhydride (33.6 g) were charged, and the resultant mixture was stirred at 100° C. for 2 hours. After completion of the reaction, acetic anhydride was removed under reduced pressure, and the residue was extracted with toluene. The toluene layer was washed with 1% sodium bicarbonate solution and water. Toluene was removed from the toluene layer to give dl-3-acetoxy-2-n-pentyl-4-cyclopentenone (19.5 g). Yield, 93%. B.P., 105°-110° C./0.2-0.5 mmHg.

Workup

  1. customInto a flask equipped with a stirrer
  2. customwas removed under reduced pressure
  3. extractionthe residue was extracted with toluene
  4. washThe toluene layer was washed with 1% sodium bicarbonate solution and water
  5. customToluene was removed from the toluene layer

Sources & evidence

ORD record
ord-b893df4b569e4ebe9b07a933b91b9ca2
Source dataset
uspto-grants-1988_03
Patent number
US04729953

Reaction notes

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