Acetic Anhydride → 5-(R)-(2-(S)-Acetylamino-1-(S)-hydroxy-3-phenyl-propyl)-2-(S)-(2-cyclohexyl-ethyl)-morpholine-4-carboxylic acid tert-butyl ester

Participants

Reaction Steps

Dissolve 5-(R)-(2-(S)-amino-1-(S)-hydroxy-3-phenylpropyl)-2-(S)-(2-cyclohexylethyl)-morpholine-4-carboxylic acid tert-butyl ester (140 mg, 0.31 mmol) in dry tetrahydrofuran (3 mL). Add triethylamine (0.05 mL, 0.35 mmol) followed by acetic anhydride (0.03 mL, 0.35 mmol) and stir at room temperature for 1 hour. Dilute with dichloromethane, wash with 0.1 N hydrochloric acid/saturated aqueous sodium chloride (30 mL), dry (sodium sulfate), filter, concentrate and purify (silica gel chromatography, eluting with 40:60 to 60:40 ethyl acetate:dichloromethane) acetate/dichloromethane to give the title compound (83 mg, 54%).

Provenance & Evidence