Reacción #47636

Ecuación de reacción

dry ice

Lithium

7-bromo-bicyclo[2.2.1]heptane

tetrahydrofuran

tetrahydrofuran

lithium

→

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

Rendimiento 63.0%

Condiciones de reacción

Tratamiento posterior

1. 1
   Otroto remove the coating
2. 2
   Otrowas cannulated into a −78° C.
3. 3
   Temperaturato warm to 25° C.
4. 4
   Concentraciónconcentrated in vacuo
5. 5
   workup.DISSOLUTIONThe residue was dissolved in diethyl ether (30 mL)
6. 6
   Extracciónextracted with a 1N aqueous sodium hydroxide solution (2×15 mL)
7. 7
   Extracciónextracted with diethyl ether (3×10 mL)
8. 8
   LavadoThe combined organic layers were washed with a saturated aqueous solution of sodium chloride
9. 9
   Secadodried over magnesium sulfate
10. 10
    Filtraciónfiltered
11. 11
    Concentraciónconcentrated in vacuo

Procedimiento

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%)

Fuente