Reaction Steps
To a stirred solution of (2S,3R,4R,5S,6R)-6-(acetoxymethyl)-3-isothiocyanato-tetrahydro-2H-pyran-2,4,5-triyl triacetate (500 mg, 1.3 mmol) in CH3CN (10 mL) was added 2-aminoethyl acetate trifluoroacetate (600 mg, 3 mmol) and triethylamine (0.5 mL, 3.5 mmol). The mixture was stirred at room temperature for 1 h. The solution was diluted with CH2Cl2 (50 mL) and washed with saturated aqueous NaHCO3 (20 mL), and the organic extract was dried (Na2SO4) and concentrated. The residue was purified by flash chromatography on silica gel (hexane/EtOAc 1:1) to give (2S,3R,4R,5S,6R)-6-(acetoxymethyl)-3-(3-(2-acetoxyethyl)thioureido)-tetrahydro-2H-pyran-2,4,5-triyl triacetate as a white foam (580 mg, 92% yield). 1H NMR (600 MHz, DMSO-d6) δ 2.06 (s, 3H), 2.08 (s, 3H), 2.11 (s, 3H), 2.12 (s, 3H), 2.15 (s, 3H), 3.66-3.80 (m, 2H), 3.85 (ddd, 1H, J=2.5, 4.5, 9.0 Hz), 4.14 (dd, 1H, J=2.0, 12.5 Hz), 4.22 (dd, 1H, J=5.0, 5.0 Hz), 4.29 (dd, 1H, J=4.5, 12.5 Hz), 4.65-4.75 (m, 1H), 5.13-5.22 (m, 2H), 5.73 (d, 1H, J=8.5 Hz).13C NMR (125 MHz, DMSO-d6) δ 20.82, 20.86, 20.98, 21.04, 21.19, 40.51, 57.21, 61.85, 62.75, 68.25, 71.84, 73.12, 92.65, 169.34, 169.73, 170.13, 170.49, 170.77, 184.26.
