To a solution of (3aR,7aS)-benzyl 2-oxohexahydrooxazolo[4,5-c]pyridine-5(6H)-carboxylate (1.0 equiv.) in dichloromethane (0.09 M) was added BOC2O (1.1 equiv.), triethylamine (1.1 equiv.), and a catalytic amount of DMAP. The reaction was stirred at room temperature for one hour at which point it was concentrated under vacuo and filtered through a plug of silica gel eluting with ethylacetate. The product was dried under vacuo to give a white solid in 75% yield. LCMS (m/z): 277.2 (MH+), LC Rt=3.43 min.
