Réaction #47636

Équation de réaction

dry ice

Lithium

7-bromo-bicyclo[2.2.1]heptane

tetrahydrofuran

tetrahydrofuran

lithium

→

bicyclo[2.2.1]hept-7-yl-acetic acid

Rendement 63.0%

Conditions de réaction

Traitement

1. 1
   Autreto remove the coating
2. 2
   Autrewas cannulated into a −78° C.
3. 3
   Températureto warm to 25° C.
4. 4
   Concentrationconcentrated in vacuo
5. 5
   workup.DISSOLUTIONThe residue was dissolved in diethyl ether (30 mL)
6. 6
   Extractionextracted with a 1N aqueous sodium hydroxide solution (2×15 mL)
7. 7
   Extractionextracted with diethyl ether (3×10 mL)
8. 8
   LavageThe combined organic layers were washed with a saturated aqueous solution of sodium chloride
9. 9
   Séchagedried over magnesium sulfate
10. 10
    Filtrationfiltered
11. 11
    Concentrationconcentrated in vacuo

Mode opératoire

Lithium metal (78 mg, 11.2 mmol) was scraped under a tetrahydrofuran solution to remove the coating and then added to a solution of 4,4′-tertbutyl biphenyl (2.67 g, 10.02 mmol) in tetrahydrofuran (15 mL) under argon. The mixture was cooled to 0° C. and a blue-green color appeared over time. After 3 h, all the lithium metal was dissolved and the mixture was cannulated into a −78° C. mixture of 7-bromo-bicyclo[2.2.1]heptane (1.0 g, 5.71 mmol) in tetrahydrofuran (5 mL). The mixture turned colorless and then developed a red color and stirred at −78° C. for 30 min. The mixture was then quickly poured over freshly crushed dry ice. The resulting yellow mixture was allowed to warm to 25° C. and concentrated in vacuo. The residue was dissolved in diethyl ether (30 mL) and extracted with a 1N aqueous sodium hydroxide solution (2×15 mL). The combined aqueous extracts were acidified with concentrated hydrochloric acid and extracted with diethyl ether (3×10 mL). The combined organic layers were washed with a saturated aqueous solution of sodium chloride, dried over magnesium sulfate, filtered and concentrated in vacuo to afford bicyclo[2.2.1]hept-7-yl-acetic acid (554 mg, 63%)

Source