Trifluoroacetic acid → (R)-2-amino-1-(3-fluoro-azetidin-1-yl)-3-methoxy-propan-1-one trifluoroacetate

In a 25 mL round-bottomed flask, [(R)-2-(3-fluoro-azetidin-1-yl)-1-methoxymethyl-2-oxo-ethyl]-carbamic acid tert-butyl ester (265 mg, 0.96 mmol) was dissolved in dichloromethane (5 ml). The reaction was cooled to 0° C. and trifluoroacetic acid (1.5 ml, 19.5 mmol) was slowly added. The reaction mixture was stirred at room temperature for 3 h then concentrated to provide (R)-2-amino-1-(3-fluoro-azetidin-1-yl)-3-methoxy-propan-1-one trifluoroacetate as a colorless viscous oil which was used without further purification.