反应详情

To a solution of (2S,4R)-1-benzyloxycarbonyl-2-[{3-(ethoxycarbonyl)-2-hydroxypropyl}oxymethyl]-4-methanesulfonyloxypyrrolidine (9.5 g) in acetic acid (150 ml) were added triethylamine (15 ml) and methanesulfonyl chloride (2 ml) at -40° C. and the mixture was stirred at the same temperature for 2 hours under nitrogen atmosphere. Resulting precipitate was filtered off and the filtrate was concentrated in vacuo to give a residue, which was dissolved in a mixture of ethyl acetate (100 ml) and water (50 ml). The organic layer was separated, washed with brine (50 ml) and dried over magnesium sulfate. Evaporation of the solvent gave a residue, which was chromatographed on silica gel (300 ml) eluting with a mixture of hexane and ethyl acetate (1:1 V/V) to give (2S,4R)-1-benzyloxycarbonyl-2-[{3-(ethoxycarbonyl)-2-methanesulfonyloxypropyl}oxymethyl]-4-methanesulfonyloxypyrrolidine (3.74 g).

1. customResulting precipitate
2. filtrationwas filtered off
3. concentrationthe filtrate was concentrated in vacuo
4. customto give a residue, which
5. customThe organic layer was separated
6. washwashed with brine (50 ml)
7. dry with materialdried over magnesium sulfate
8. customEvaporation of the solvent
9. customgave a residue, which
10. customwas chromatographed on silica gel (300 ml)
11. washeluting with a mixture of hexane and ethyl acetate (1:1 V/V)