反应详情

To a solution of (2S,4R)-1-allyloxycarbonyl-2-(2-hydroxyethyloxymethyl)-4-methanesulfonyloxypyrrolidine (28.0 g) and thioacetic S-acid (12.47 ml) in 4-methyl-2-pentanone (168 ml) was added calcium hydroxide (6.41 g) below 45° C. Under reduced pressure (50-60 mmHg), the solvent (60 ml) was removed at 40°-50° C. The resulting suspension was heated at 80°-85° C. for 15 hours. After cooling, insoluble material was filtered off and washed with ethyl acetate (50 ml). The filtrate and washing were combined, dried over magnesium sulfate, and concentrated under reduced pressure to give a syrup. The syrup was subjected to a column chromatography on silica gel (280 g) and eluted with a mixture of methanol and dichloromethane (1:99 V/V) to give (2S,4S)-4-acetylthio-1-allyloxycarbonyl-2-(2-hydroxyethyloxymethyl)pyrrolidine (10.74 g).

1. customUnder reduced pressure (50-60 mmHg), the solvent (60 ml) was removed at 40°-50° C
2. temperatureThe resulting suspension was heated at 80°-85° C. for 15 hours
3. temperatureAfter cooling
4. filtrationinsoluble material was filtered off
5. washwashed with ethyl acetate (50 ml)
6. washThe filtrate and washing
7. dry with materialdried over magnesium sulfate
8. concentrationconcentrated under reduced pressure
9. customto give a syrup
10. washeluted with a mixture of methanol and dichloromethane (1:99 V/V)