4-Nitrobenzenesulfonyl chloride → (3R,3aS,6aR)hexahydrofuro[2,3-b]furan-3-yl (1S,2R)-1-benzyl-3-{(1-ethylpropoxy)[(4-nitrophenyl)sulfonyl]amino}-2-hydroxypropylcarbamate

Participants

Reaction Steps

A mixture of (3R,3aS,6aR)hexahydrofuro[2,3-b]furan-3-yl (1S,2R)-1-benzyl-3-[(1-ethylpropoxy)amino]-2-hydroxypropylcarbamate (200 mg, 0.474 mmol), 4-nitrophenylsulphonyl chloride (105 mg, 0.474 mmol), diisoproylethylamine (0.084 mL, 0.474 mmol) and dimethylaminopyridine (˜1 mg) in anhydrous tetrahydrofuran (3 mL) was stirred at ambient temperature over 16 hours under an Argon atmosphere. The reaction was evaporated in vacuo and the residue was partitioned between dichloromethane and aqueous sodium hydrogen sulfate (1N). The phases were separated and the aqueous layer was extracted with dichloromethane. The combined organic phases were dried over anhydrous magnesium sulfate, filtered and evaporated in vacuo. The residue was purified on flash grade silica gel eluting with 1:1 ethyl acetate:hexane. Fractions containing the product were combined, evaporated in vacuo and dried under high vacuum to provide (3R,3aS,6aR)hexahydrofuro[2,3-b]furan-3-yl (1S,2R)-1-benzyl-3-{(1-ethylpropoxy)[(4-nitrophenyl)sulfonyl]amino}-2-hydroxypropylcarbamate (254 mg, 88%) as a foam. H1-NMR (chloroform-D3): 0.90 (m, 6H), 1.60 (m, 7H), 2.90 (m, 5H), 3.68 (m, 2H), 3.87 (m, 4H), 4.17 (m, 1H), 4.83 (d, 1H), 5.02 (m, 1H), 5.64 (d, 1H), 7.23 (m, 5H), 7.99 (d, 2H), 8.38 (d, 2H). MS(ESI): 630(M+Na).

Provenance & Evidence