反应详情

温度

-78 °C

6.9 g (40 mmol) of 5-(1,3-dithian-2-yl)-1-methylimidazole are dissolved in 190 ml of tetrahydrofuran and cooled to -78° C. 40 mmol of n-BuLi in 24 ml of hexane are added dropwise to this and, after 30 minutes, at -78° C., 3.8 ml (54 mmol) of γ-crotonolactone are added. After a further 1.5 hours at -78° C., 190 ml of water are added dropwise, and the mixture is warmed to room temperature. It is subsequently acidified with glacial acetic acid, the organic layer is separated off, and the aqueous phase is washed several times with ethyl acetate. The combined organic extracts are dried over magnesium sulfate and subsequently concentrated in vacuo. The residue is chromatographed on silica gel with dichloromethane/methanol (9:1). 3.1 g (10.9 mmol, 27%) of 3-(2-(1-methylimidazol-5-yl)-1,3-dithian-2-yl)butyrolactone are obtained as a yellow oil in this way.

1. temperaturethe mixture is warmed to room temperature
2. customthe organic layer is separated off
3. washthe aqueous phase is washed several times with ethyl acetate
4. dry with materialThe combined organic extracts are dried over magnesium sulfate
5. concentrationsubsequently concentrated in vacuo
6. customThe residue is chromatographed on silica gel with dichloromethane/methanol (9:1)