Reaction Steps
To a solution of (3R,3aS,6aR)-hexahydrofuro[2,3-b]furan-3-yl (1S,2R)-3-[(1,3-benzodioxol-5-ylsulfonyl)(isobutyl)amino]-2-hydroxy-1-(4-hydroxybenzyl)propylcarbamate (47 mg, 0.08 mmol) in anhydrous dimethylformamide (2 mL) was added cesium carbonate (78 mg, 0.24 mmol) and 2-bromoacetamide (22 mg, 0.16 mmol). After 1 h at ambient temperature, the mixture was diluted with ethyl acetate, washed with water (3×), brine, dried (sodium sulfate), and evaporated. The residue was purified by chromatography (silica gel, dichloromethane/methanol, 97:3) to afford the title product as a white solid (45 mg). 1H NMR (DMSO-d6): δ 0.78 (3H, d), 0.82 (3H, d), 1.2 (1H, dd), 1.4 (1H, quintuplet), 1.9-2.0 (1H, m), 2.35 (1H, t), 2.6-2.8 (3H, m), 2.9 (1H, d), 2.95 (1H, dd), 3.25-3.30 (1H, m), 3.45 (1H, br s), 3.5-3.6 (3H, m), 3.7 (1H, t), 3.8 (1H, dd), 4.3 (2H, s), 4.8 (1H, dt), 5.0 (1H, d), 5.5 (1H, d), 6.18 (2H, s), 6.8 (2H, d), 7.0-7.15 (3H, m), 7.22 (1H, s), 7.24 (1H, d), 7.26 (1H, d), 7.32 (1H, s), 7.42 (1H, s); MS: 650 (MH+)
