Реакция #554572

Уравнение реакции

NaOH

15a

Methyl 6-trityloxy-hexanoate

NaOH

→

white powder 16a

Выход 78.1%

6-Trityloxyhexanoic acid

Выход 78.1%

Растворители

THF

water

Условия реакции

Обработка

1. 1
   workup.STIRRINGstirring
2. 2
   workup.WAITwas continued for another 2 days
3. 3
   ДругоеThe THF was removed under reduced pressure
4. 4
   Экстракцияextracted with diethyl ether
5. 5
   ПромывкаThe combined organic layers were washed with brine
6. 6
   Сушкаdried over MgSO4
7. 7
   ДругоеThe diethyl ether was removed under reduced pressure
8. 8
   Другоеthe resulting crude powder was recrystalized in hexanes

Методика

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]+.

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