Reacción #76269

Ecuación de reacción

NH4Cl

Methanol

LiBH4

ethyl 5-bromo-2-methyl-2-phenyl-pentanoate

→

5-bromo-2-methyl-2-phenyl-pentan-1-ol

Rendimiento 96.8%

Disolventes

CH2Cl2

Condiciones de reacción

Tratamiento posterior

1. 1
   Temperaturathe reaction mixture was heated
2. 2
   Temperaturato reflux overnight
3. 3
   OtroThe layers were separated
4. 4
   Extracciónthe aqueous layer was extracted with CH2Cl2 (3×150 mL)
5. 5
   LavadoThe combined organic layers were washed with NH4Cl solution (3×100 mL)
6. 6
   Secadodried over MgSO4
7. 7
   Concentraciónconcentrated in vacuo

Procedimiento

Methanol (5.24 g, 164 mmol) was added drop-wise to a stirred suspension of LiBH4 (3.45 g, 150 mmol) in anhydrous CH2Cl2 (150 mL) under N2 atmosphere. After the addition of ethyl 5-bromo-2-methyl-2-phenyl-pentanoate (23.70 g, 106 mmol), the reaction mixture was heated to reflux overnight. The reaction mixture was cooled to 5° C. and hydrolyzed with ice (ca. 30 g) and NH4Cl solution (150 mL) for 1 h. The layers were separated and the aqueous layer was extracted with CH2Cl2 (3×150 mL). The combined organic layers were washed with NH4Cl solution (3×100 mL), dried over MgSO4 and concentrated in vacuo to furnish 5-bromo-2-methyl-2-phenyl-pentan-1-ol (20 g, 96.8%) as an oil. 1H NMR (300 MHz, CDCl3/TMS): δ (ppm) 7.34-7.14 (m, 5H), 3.60 (m, 1H), 3.48 (m, 1H), 3.29 (t, J=6.0 Hz, 2H), 1.96-1.44 (m, 5H), 1.32 (s, 3H). 13C NMR (75 MHz, CDCl3/TMS): δ (ppm) 144.25, 128.59, 126.71, 126.41, 72.44, 43.15, 37.06, 34.64, 27.58, 21.61. HRMS (LSIMS, nba): Calcd. for C2H16Br (MH+—H2O): 239.0435, found: 239.0444.

Fuente