Trifluoroacetic acid → (2S,4R)-4-hydroxy-2-(5-methyl-oxazol-2-yl)-pyrrolidine-1-carboxylic acid benzyl ester

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Reaction Steps

To a stirred solution of (2S,4R)-4-tert-butoxy-2-(5-methyl-oxazol-2-yl)-pyrrolidine-1-carboxylic acid benzyl ester (2 g, 5.59 mmol) in dichloromethane (15 mL) was added trifluoroacetic acid (1.57 mL) in dichloromethane (1:5) at 0° C. and the mixture was then stirred at room temp. for 16 h. The reaction mixture was neutralized with saturated sodium bicarbonate solution and extracted with dichloromethane. The organic layer was washed with brine, dried over anhydrous sodium sulfate and concentrated under reduced pressure. The crude was then purified by column chromatography to give (2S,4R)-4-hydroxy-2-(5-methyl-oxazol-2-yl)-pyrrolidine-1-carboxylic acid benzyl ester (1.1 g, 65.1% yield) as an off white solid. MS calcd. for C16H19N2O4 [(M+H)+] 303.0, obsd. 303.4.

Provenance & Evidence