Réaction #345626

Équation de réaction

hydrochloric acid

lithium diisopropyl amide

(-)-2-norbornanone

allyl bromide

→

3-allyl-2-norbornanone

Solvants

tetrahydrofuran hexane

tetrahydrofuran

tetrahydrofuran

Conditions de réaction

Traitement

1. 1
   workup.STIRRINGthe mixture was stirred at -20° C. for 30 minutes
2. 2
   Températurethe temperature of the mixture was raised to room temperature
3. 3
   workup.STIRRINGthe mixture was stirred for one hour
4. 4
   Extractionthe mixture was extracted with toluene (50 ml×4)
5. 5
   LavageThe extract was washed with successive, saturated sodium bicarbonate solution, water, saturated sodium chloride (each 50 ml), and
6. 6
   Séchagedried over anhydrous magnesium sulfate
7. 7
   FiltrationThe solution was filtered
8. 8
   workup.DISTILLATIONthe solvent was distilled off

Mode opératoire

To 3.4 ml (6.8 mmol) of a 2M solution of lithium diisopropyl amide in tetrahydrofuran-hexane, 1 ml of a solution of 500 mg (4.54 mmol) of (-)-2-norbornanone in tetrahydrofuran was added dropwise at -40° C., and the mixture was stirred at -20° C. for 10 minutes. Then, 1 ml of a solution of 540 mg (4.46 mmol) of allyl bromide in tetrahydrofuran was added dropwise, the mixture was stirred at -20° C. for 30 minutes, the temperature of the mixture was raised to room temperature, and the mixture was stirred for one hour. On ice cooling, the reaction mixture was poured into 20 ml of 1N hydrochloric acid, and the mixture was extracted with toluene (50 ml×4). The extract was washed with successive, saturated sodium bicarbonate solution, water, saturated sodium chloride (each 50 ml), and dried over anhydrous magnesium sulfate. The solution was filtered, and the solvent was distilled off to obtain 980 mg of crude 3-allyl-2-norbornanone. The product was purified by distillation, and 550 mg (3.66 mmol) of (-)-exo-3-allyl-2-norbornanone was obtained. Yield: 81%.

Source