13613-65-5

3976-69-0

13613-65-5

In a 500 mL three-necked flask, methyl (R)-3-hydroxybutyrate (76.0 g) made from Example 1 was added, followed by 300 mL of water. The reaction temperature was controlled to be below 30 °C, and sodium hydroxide (25.8 g) was added slowly in batches over a period of 3 hours. After addition, maintain the temperature no higher than 10°C and continue to stir the reaction for 3 hours until the reaction is complete. Add 0.3 g of activated carbon and filter after continuous stirring for 0.5 hours. The filtrate was concentrated to 100 mL, at which time a large amount of solid precipitated. Crystallization was stirred at room temperature for 1 hour, centrifuged and dried in vacuum to obtain 68.9 g of (R)-(-)-3-hydroxybutyric acid sodium salt as a white solid with a yield of 85.0% and an ee value of 91.5%.