Réaction #219954

Équation de réaction

ethyl 2-oxocyclopentane carboxylate

potassium carbonate

1-bromo-iso-pentane

→

Ethyl 1-iso-pentyl-2-oxocyclopentane carboxylate

Rendement 72.6%

Solvants

acetone

Conditions de réaction

Traitement

1. 1
   workup.STIRRINGThe reaction mixture was further stirred for about 15 minutes
2. 2
   workup.ADDITIONUpon the completion of the addition
3. 3
   Températurethe reaction mixture was heated
4. 4
   Températurefor reflux for 6 hours
5. 5
   FiltrationThe reaction mixture was filtered under the reduced pressure
6. 6
   Lavagethe filter cake was washed with diethyl ether until its color
7. 7
   AutrePale yellow filtrate was collected
8. 8
   Séchagedried over anhydrous magnesium sulfate
9. 9
   Autrethe solvent was removed
10. 10
    workup.DISTILLATIONThe residue was distilled under reduced pressure, and 32.80 g of colorless liquid as a distillate cut of 142-147° C./15 mmHg
11. 11
    Autrewas collected

Mode opératoire

Under vigorous agitation, 34.67 g (purity of 90%) of ethyl 2-oxocyclopentane carboxylate was added to 112.65 g (purity of 98%,) of ground anhydrous potassium carbonate, and after stirring for several minutes, to the mixture was added 100 ml of acetone. The reaction mixture was further stirred for about 15 minutes, then thereto was dropwise added 51.36 ml (purity of 98%) of 1-bromo-iso-pentane. Upon the completion of the addition, the reaction mixture was heated for reflux for 6 hours. The reaction mixture was filtered under the reduced pressure, and the filter cake was washed with diethyl ether until its color was purely white. Pale yellow filtrate was collected and dried over anhydrous magnesium sulfate, then the solvent was removed. The residue was distilled under reduced pressure, and 32.80 g of colorless liquid as a distillate cut of 142-147° C./15 mmHg was collected. Yield: 72.60%. MS: m/e 227(M30 +1), 226(M+), 211 (M+—CH3) 198(M+—CH2CH2) 171 (M+—OCH2CH3), 156 (M+—C5H11, base), 153(M+—CO2 CH2CH3), 127(155-CH2CH2), 111(156-OCH2CH3), 55.

Source