Reaction Steps
To a stirred solution of (3S,3aS,6aR)-hexahydrofuro[2,3-b]furan-3-yl (4S,5R)-5-{[[(4-aminophenyl)sulfonyl](isobutyl)amino]methyl}-4-{4-[(3-cyanobenzyl)oxy]benzyl}-2,2-dimethyl-1,3-oxazolidine-3-carboxylate in 3 mL of dioxane was added 4M hydrochloric acid in dioxane (1.5 mL) and water (0.05 mL). The solution was stirred for 1 hour followed by neutralization with 10% aqueous Na2CO3. The solution was extracted with dichloromethane (3×15 mL). The organic phase was dried with magnesium sulfate, filtered, and concentrated under reduced pressure. The residue was purified on silica gel using ethyl acetate-hexanes (8:2) as eluent to provide 17 mg (61%) of the title compound. 1H-NMR (DMSO-d6): δ 0.74 (3H,d), 0.81(3H,d), 1.18 (1H,m), 1.28 (1H,m), 1.89 (1H,m), 2.35 (1H,t), 2.54-2.60 (2H,m), 2.71 (1H,m), 2.86-2.93 (2H,m), 3.22-3.29 (1H,dd), 3.42-3.48 (1H,m), 3.53-3.59 (3H,m), 3.65 (1H,t), 3.82 (1H,q), 4.80 (1H,q), 4.93 (1H,d,b), 5.07 (2H,s), 5.47 (1H,d), 5.94 (2H,s,b), 6.54 (2H,d), 6.83 (2H,d), 7.08 (2H,d), 7.19 (1H,d), 7.33 (2H,d), 7.56 (1H,t), 7.74 (2H,t), 7.85 (1H,s). MS: 680 (M+).
