35677-88-4

672-15-1

501-53-1

35677-88-4

General procedure for the synthesis of (S)-2-(((benzyloxy)carbonyl)amino)-4-hydroxybutyric acid from L-homoserine and benzyl chloroformate: L-homoserine (4.76 g, 40 mmol) was dissolved in a solvent mixture of H2O (200 mL) and 1,4-dioxane (50 mL). To this solution was added NaHCO3 (13.44 g, 160 mmol), followed by slow dropwise addition of benzyl chloroformate (6.76 mL, 48 mmol). The reaction mixture was stirred at room temperature overnight. After completion of the reaction, the mixture was washed twice with ethyl acetate (EA). The aqueous layer was neutralized to pH 2 with 4 mol/L HCl solution and then extracted with EtOAc. The organic layers were combined, washed sequentially with water and brine, dried over anhydrous Na2SO4 and concentrated to dryness under reduced pressure. The resulting crude product (8.86 g, 35 mmol, 87.5% yield) was used directly in the next reaction without further purification.