Methanesulfonyl chloride → 1-tert-Butyl 2-methyl (2S,4R)-4-((methanesulfonyl)oxy)pyrrolidine-1,2-dicarboxylate

Participants

Reaction Conditions

Reaction Steps

To a solution of (2S,4R)-N-tert-butoxycarbonyl-4-hydroxyproline methyl ester (30.2 g, 123 mmol) in methylene chloride (300 ml) were dropwise added successively triethylamine (41.2 ml, 0.295 mmol) and methanesulfonyl chloride (17.1 ml, 0.221 mol) at 0° C. in a nitrogen atmosphere. The mixture was stirred at 0° C. for 2 h, and saturated aqueous sodium hydrogencarbonate was added. The mixture was extracted with ethyl acetate. The organic layer was washed with saturated aqueous sodium chloride, and dried over anhydrous magnesium sulfate. The solvent was removed in vacuo. The residue was subjected to silica gel flash column chromatography (heptane-ethyl acetate=5:5) to give (2S,4R)-N-tert-butoxycarbonyl-4-methanesulfonyloxyproline methyl ester (39.5 g, yield: 99.1%).

Provenance & Evidence