4-(2-Hydroxymethylfuran-3-yl)piperidine-1-carboxylic acid t-butyl ester (0.3 g, 1.1 mmol, 1.0 eq.) was dissolved in DCM (5.7 mL). The mixture was cooled to 0° C. and DABCO (132 mg, 1.2 mmol, 1.1 eq.) was added, followed by TsCl (224 mg, 1.2 mmol, 1.1 eq.). The mixture was stirred at 0° C. for 90 minutes, then diluted with EtOAc (500 ml) and washed with water (2×250 mL). The organic layer was dried over anhydrous Na2SO4, filtered and concentrated by rotary evaporation to yield the title compound (340 mg), which was used without further purification.
