1,3-Cyclohexanedione, 2-chloro-2-(2-propenyl)- → 2-Cyclopenten-1-one, 2-(2-propenyl)-

HRID 372181Notes

Reaction equation

HRID 372181 reaction equation
Cl[C:2]1([CH2:10][CH:11]=[CH2:12])[C:7](=[O:8])[CH2:6][CH2:5][CH2:4]C1=O>C1(C)C(C)=CC=CC=1>[CH2:10]([C:2]1[C:7](=[O:8])[CH2:6][CH2:5][CH:4]=1)[CH:11]=[CH2:12]

Participants

3

Reactant 1

HCID 122296551,3-Cyclohexanedione, 2-chloro-2-(2-propenyl)-

Product 1

HCID 111160462-Cyclopenten-1-one, 2-(2-propenyl)-Yield 50%

Reagents, catalysts & solvents 1

HCID 7237O-XyleneSolvent

Procedure

Anhydrous powdered sodium carbonate (670 g) and 1300 ml of dry (alumina) xylene were placed in a 3-l., three-necked flask equipped with a Dean-Stark trap, condenser, vibra-mixer, dropping funnel and argon inlet. The flask was flushed with argon and the contents brought to reflux. A solution of 2-chloro-2-allyl-1,3-cyclohexanedione (147 g, 0.79 mol) in 200 ml of xylene was added dropwise at such a rate that strong refluxing was maintained. After 4.5 hr, the reaction was cooled, filtered, and the sodium carbonate cake washed thoroughly with ethyl acetate. Evaporation of the solvent and careful fractionization of the residual oil gave 47.8 g (50 percent) of 2-allyl-2-cyclopenten-1-one, bp 73°-84°/4.2 mm.

Workup

  1. dry with materialAnhydrous powdered sodium carbonate (670 g) and 1300 ml of dry (alumina) xylene
  2. custom, three-necked flask equipped with a Dean-Stark trap, condenser, vibra-mixer
  3. customThe flask was flushed with argon
  4. temperatureto reflux
  5. temperaturethat strong refluxing
  6. temperaturewas maintained
  7. temperaturethe reaction was cooled
  8. filtrationfiltered
  9. washthe sodium carbonate cake washed thoroughly with ethyl acetate
  10. customEvaporation of the solvent and careful fractionization of the residual oil

Sources & evidence

ORD record
ord-9034c41cfb394192b1eed1d5114bd854
Source dataset
uspto-grants-1978_05
Patent number
US04089889

Reaction notes

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