反应详情

To a solution of (2S,4R)-1-allyloxycarbonyl-2-(2-fluoroethyloxymethyl)-4-methanesulfonyloxypyrrolidine (17.30 g) and thioacetic S-acid (5.88 ml) in 4-methyl-2-pentanone (121 ml) was added calcium hydroxide (3.05 g) below 45° C. Solvent (40 ml) was removed under reduced pressure (50-60 mmHg), at 40°-45° C. The suspension was heated at 80°-85° C. for 5 hours. After cooling, water (30 ml) was added to the suspension. The insoluble material was filtered off and washed with ethyl acetate (50 ml). The filtrate and washing were collected. The organic layer was dried over magnesium sulfate and concentrated under reduced pressure to give a syrup. The syrup was subjected to a column chromatography on silica gel (170 g) and eluted with a mixture of hexane and ethyl acetate (1:9-2:8) to give (2S,4S)-4-acetylthio-1-allyloxycarbonyl-2-(2-fluoroethyloxymethyl)pyrrolidine (13.80 g).

1. customSolvent (40 ml) was removed under reduced pressure (50-60 mmHg), at 40°-45° C
2. temperatureThe suspension was heated at 80°-85° C. for 5 hours
3. temperatureAfter cooling
4. additionwater (30 ml) was added to the suspension
5. filtrationThe insoluble material was filtered off
6. washwashed with ethyl acetate (50 ml)
7. washThe filtrate and washing
8. customwere collected
9. dry with materialThe organic layer was dried over magnesium sulfate
10. concentrationconcentrated under reduced pressure
11. customto give a syrup
12. washeluted with a mixture of hexane and ethyl acetate (1:9-2:8)