5-Chlorothiophene-2-sulfonyl chloride (2.42 g, 11.55 mmol) was added dropwise (5 min) as a solution in CH2Cl2 (20 mL) to a 0° C. solution of (4R)-3-[(2S)-2-azido-3-butylheptanoyl]-4-benzyl-1,3-oxazolidin-one (1.9 g, 10.14 mmol) and triethylamine (2.11 mL, 15.21 mmol). The solution was allowed to warm to 25° C. overnight (19 h). An aliquot was taken and TLC (1:1 EtOAc-hexane) indicated that reaction was complete. It was diluted with CH2Cl2 (100 mL) and the organic layer was washed with IN HCl (2×50 mL) and saturated aqueous NaCl (50 mL). The organic layer was dried over MgSO4, filtered, and concentrated to obtain a crude oil (2.98 g). The crude product was purified by column chromatography, silica gel 230-400 mesh, eluent: starting with 1:3 EtOAc-hexane and ending with 1:2 EtOAc-hexane to furnish N-[(1S)-2-butyl-1-(hydroxymethyl)hexyl]-5-chloro-2-thiophenesulfonamide as an amorphous white solid (0.630 g, 16.9%). Mass Spectrum (−ESI): 366 (M−H)−. Anal. Calc'd for C15H25NClO3S2: C, 48.96; H, 7.12; N, 3.81. Found: C, 49.08, H, 6.83, N, 3.82.
