反应详情

Under a nitrogen atmosphere, to a solution of (S)-(+)-3-hydroxybutyric acid ethyl ester (100 g, 0.76 mol) in methylene chloride (1.0 L), benzyl 2,2,2-trichloroacetoimidate (381 g, 1.5 mol) and trifluoromethanesulfonic acid (6.7 mL, 76 mmol) were gradually added, and the mixture was stirred at room temperature overnight. The precipitated solid was filtered, and after the mother liquid was successively washed with a saturated aqueous sodium hydrogencarbonate solution, water and saturated brine, it was dried with sodium sulfate and the solvent was distilled off under reduced pressure. Hexane was added to the residue, and after the solid was filtered again, the solvent of the mother liquid was distilled off under reduced pressure to give (3S)-3-(benzyloxy)butanoic acid ethyl ester (339 g) as a mixture. The present compound was used for the subsequent reaction without further purification.

1. filtrationThe precipitated solid was filtered
2. washafter the mother liquid was successively washed with a saturated aqueous sodium hydrogencarbonate solution, water and saturated brine, it
3. dry with materialwas dried with sodium sulfate
4. distillationthe solvent was distilled off under reduced pressure
5. additionHexane was added to the residue
6. filtrationafter the solid was filtered again
7. distillationthe solvent of the mother liquid was distilled off under reduced pressure