反应详情

A solution of stearic anhydride (1.14 g, 2.06 mmol) in dichloromethane (30 mL) was cannulated into a stirred solution of ethylene glycol (1.10 mL, 19.7 mmol), DMAP (22 mg, 0.18 mmol) and triethylamine (0.300 mL, 2.16 mmol) in dichloromethane (20 mL). After stirring for 90 min. the reaction was quenched with the addition of H2O (100 mL). After separation of the phases the aqueous fraction was re-extracted with dichloromethane (2×50 mL) and the combined organic extract was washed with brine (70 mL). After drying (MgSO4) and filtration the solvent was removed at reduced pressure to give the crude product that was purified by chromatography on silica gel. Gradient elution with ethyl acetate/petroleum ether (10:90→30:70) afforded the title compound 48 (265 mg, 0.807 mmol, 39%) as an oil; 1H NMR (300 MHz, CDCl3) δ 4.25-4.20 (m, 2H), 3.83-3.78 (m, 2H), 2.38 (t, 2H, J 7.5 Hz), 2.00-1.97 (m, 1H), 1.62-1.55 (m, 2H), 1.35-1.20 (m, 28H), 0.87-0.81 (m, 3H); 13C NMR (75 MHz, CDCl3) δ 174.6, 66.3, 61.7, 34.6, 32.3, 30.1, 29.8, 29.7, 29.6, 29.5, 25.3, 23.1, 14.5; HRMS-ESI (+ve) (Found: m/z 346.3323 (MNH4+). C20H44NO3 requires m/z 346.3316).

1. customwas quenched with the addition of H2O (100 mL)
2. customAfter separation of the phases the aqueous fraction
3. extractionwas re-extracted with dichloromethane (2×50 mL)
4. extractionthe combined organic extract
5. washwas washed with brine (70 mL)
6. customAfter drying
7. filtration(MgSO4) and filtration the solvent
8. customwas removed at reduced pressure
9. customto give the crude product that
10. customwas purified by chromatography on silica gel
11. washGradient elution with ethyl acetate/petroleum ether (10:90→30:70)