反应详情

Under nitrogen atmosphere at -70° C., to a solution of oxalyl chloride (4.31 ml) in dichloromethane (200 ml) were added dropwise dimethyl sulfoxide (7.01 ml), a solution of (2S,4R)-1-benzyloxycarbonyl-2-(2-hydroxyethyloxymethyl)-4-methanesulfonyloxypyrrolidine (17.57 g) in dichloromethane (50 ml) and triethylamine (37.8 ml). The reaction mixture was stirred at the same temperature for 2 hours and then allowed to warm to ambient temperature. Precipitate was filtered off and to the filtrate was added a mixture of ethyl acetate (200 ml) and water (100 ml). The organic layer was separated, washed with brine (100 ml), dried over magnesium sulfate and active carbon was added thereto. Evaporation of the solvent gave a residue, which was chromatographed on silica gel (500 ml) eluting with a mixture of dichloromethane and methanol (9:1 V/V) to give (2S,4R)-1-benzyloxycarbonyl-2-(2-oxoethyl)oxymethyl-4-methanesulfonyloxypyrrolidine (15.7 g).

1. filtrationPrecipitate was filtered off and to the filtrate
2. additionwas added
3. additiona mixture of ethyl acetate (200 ml) and water (100 ml)
4. customThe organic layer was separated
5. washwashed with brine (100 ml)
6. dry with materialdried over magnesium sulfate and active carbon
7. additionwas added
8. customEvaporation of the solvent
9. customgave a residue, which
10. customwas chromatographed on silica gel (500 ml)
11. washeluting with a mixture of dichloromethane and methanol (9:1 V/V)