Reaction Steps
To a stirring solution of (2S,3R)-1-azido-3-benzyloxy-4-penten-2-ol (1) (250 μL, 1.07 mmol) in THF (50 mL) under argon was added tetrabutylammonium iodide (42 mg, 0.11 mmol) followed by benzyl bromide (155 μL, 1.27 mmol) and the reaction was cooled to 0° C. Sodium hydride (60% in mineral oil, 47 mg, 1.18 mmol) was added in small portions and the reaction was stirred overnight with warming to rt. The reaction was quenched with MeOH, filtered through Celite, and washed with Et2O. The organic solvent was removed under vacuum to give an oily residue, which was purified by flash chromatography (silica gel, 2% Et2O/hex) to yield (3R,4S)-5-azido-3,4-bisbenzyloxy-pent-1-ene (2, 237 mg, 65% yield) as a clear non-volatile liquid: Rf=0.62 (1:4 EtOAc/hex); [α]D=−6.1° (c 1.50, CHCl3); 1H NMR (CDCl3, 300 MHz) δ 7.35-7.24 (m, 10H), 5.81 (ddd, J=17.15, 10.58, 7.45 Hz, 1H), 5.37 (ddd, J=5.70, 1.65, 0.86 Hz, 1H), 5.33 (ddd, J=12.07, 1.44, 0.81 Hz. 1H), 4.63 (s, 2H), 4.61 (d, J=11.87 Hz, 1H), 4.35 (d, J=11.78 Hz, 1H), 3.90 (tdd, J=7.37, 5.65, 0.79, 0.79 Hz, 1H), 3.60 (ddd, J=6.39, 5.69, 3.64 Hz, 1H), 3.43 (dd, J=12.93, 6.42 Hz, 1H), 3.35 (dd, J=12.93, 3.60 Hz, 1H); 13C NMR (CDCl3, 75 MHz) δ 138.25, 138.01, 135.43, 128.60 (4C), 128.29 (2C), 128.02, 127.99 (2C), 127.87, 119.97, 80.76, 80.23, 73.33, 70.79, 51.69; FTIR (NaCl): 2867, 2100, 1606, 1454, 1286, 1095, 1073.
