反应详情

Trifluoromethanesulfonic acid (1.0 mL) was added gradually to a stirred mixture of ethyl lactate (8.90 g, 75 mmole), benzyl 2,2,2-trichloroacetimidate (22.7 g, 90 mmole), anhydrous cyclohexane (100 mL), and anhydrous dichloromethane (50 mL). The mixture was stirred overnight at room temperature under argon atmosphere. The mixture was filtered, and the filtrate was washed with saturated solution of sodium hydrogen carbonate (250 mL), and with distilled water (250 mL). Then, the solution was dried with anhydrous sodium sulfate and the solvents were distilled under reduced pressure using a rotary evaporator. The residue was subjected to fractional vacuum distillation giving 9.6 g of colorless product. NMR (CDCl3): 1.21 ppm (t, —CH2CH3, 3H), 1.32 ppm (d, —CH2—, 3H), 4.13 ppm (m, —CH— and —CH2CH3, 3H), 4.50 ppm (m, —CH2—, 2H), 7.32 ppm (m, 5H).

1. filtrationThe mixture was filtered
2. washthe filtrate was washed with saturated solution of sodium hydrogen carbonate (250 mL)
3. dry with materialThen, the solution was dried with anhydrous sodium sulfate
4. distillationthe solvents were distilled under reduced pressure
5. customa rotary evaporator
6. distillationThe residue was subjected to fractional vacuum distillation