D-Methionine → (2R)-2-Hydroxy-4-(methylthio)butanoic acid

Participants

Reaction Steps

D-Methionine (100 g, 0.67 mol) was dissolved in 600 ml of 10% H 2SO4 and cooled to 0°-5° C. A solution of NaNO2 (58 g, 0.84 mol) in 100 ml of H2O, also chilled to 0°-5° C., was added dropwise over 1.5 hours, maintaining the temperature of the reaction mixture at 10° C. or less by means of an ice water bath. After stirring for 18 hours at room temperature, the mixture was extracted 9×200 ml ethyl acetate. The organic extracts were combined, dried over MgSO4, and stripped to yield 10.1 g of title product as oil; tlc Rf 0.15 (ethyl acetate), 0.08 (1:1 hexane:ethyl acetate).

Provenance & Evidence