Reacción #554572

Ecuación de reacción

NaOH

15a

Methyl 6-trityloxy-hexanoate

NaOH

→

white powder 16a

Rendimiento 78.1%

6-Trityloxyhexanoic acid

Rendimiento 78.1%

Disolventes

THF

water

Condiciones de reacción

Tratamiento posterior

1. 1
   workup.STIRRINGstirring
2. 2
   workup.WAITwas continued for another 2 days
3. 3
   OtroThe THF was removed under reduced pressure
4. 4
   Extracciónextracted with diethyl ether
5. 5
   LavadoThe combined organic layers were washed with brine
6. 6
   Secadodried over MgSO4
7. 7
   OtroThe diethyl ether was removed under reduced pressure
8. 8
   Otrothe resulting crude powder was recrystalized in hexanes

Procedimiento

An aqueous solution of 5 M NaOH (17.5 mL, 87.5 mmol) was added to a stirring solution of 15a (20.1 g, 51.6 mmol) in 130 mL of THF and 52.5 mL of water at room temperature. After stirring for 2 days, 3.1 mL of 5 M NaOH (15.5 mmol) was added, and stirring was continued for another 2 days. The THF was removed under reduced pressure, then the aqueous residue was acidified with 1 M HCl to pH 5 and extracted with diethyl ether. The combined organic layers were washed with brine and dried over MgSO4. The diethyl ether was removed under reduced pressure, and the resulting crude powder was recrystalized in hexanes to yield 15.1 g (78%) of white powder 16a. Mp 114-116° C. 1H-NMR (400 MHz, CDCl3, δH ppm): 7.43 (6H, m, p-Ar), 7.28 (6H, m, m-Ar), 7.22 (3H, m, o-Ar), 3.05 (2H, t, 3JH—H=6.4 Hz, HO—CH2), 2.33 (2H, t, 3JH—H=7.5 Hz, CH2CO2), 1.56-1.68 (4H, m, 2CH2), 1.36-1.47 (2H, m, CH2). 13C-NMR (100 MHz, CDCl3, δH ppm): 180.26, 144.36, 128.62, 127.66, 126.79, 86.30, 63.24, 33.98, 29.63, 25.74, 24.48. HRMS (EI): m/z calcd 374.1882 (C25H26O3), found 374.1883 [M]+.

Fuente