反应详情

A solution of 4-benzyl-2-(2-methyl-1,3-dioxolan-2-yl)morpholine (4.25 g) in methanol (42 ml) was hydrogenated under atmospheric pressure of hydrogen over 20% palladium hydroxide on carbon (1.0 g) for 30 hours at ambient temperature. The catalyst was filtered off and the filtrate was concentrated under reduced pressure to give an oil. To a solution of the oil in a mixture of water (50 ml) and tetrahydrofuran (50 ml) was added a solution of allyl chloroformate (1.8 ml) in tetrahydrofuran (4 ml) under ice-cooling with stirring, while keeping the pH between 8.5 and 9.5 with 4N aqueous sodium hydroxide. After stirring for one hour, the mixture was extracted with ethyl acetate (100 ml), washed with brine (50 ml), dried over magnesium sulfate, and concentrated under reduced pressure to give a syrup. The syrup was subjected to a column chromatography on silica gel (50 g) and eluted with a mixture of methanol and chloroform (2:98, V/V) to give 4-allyloxycarbonyl-2-(2-methyl-1,3-dioxolan-2-yl)morpholine (2.26 g) as a syrup.

1. filtrationThe catalyst was filtered off
2. concentrationthe filtrate was concentrated under reduced pressure
3. customto give an oil
4. temperaturecooling
5. stirringAfter stirring for one hour
6. extractionthe mixture was extracted with ethyl acetate (100 ml)
7. washwashed with brine (50 ml)
8. dry with materialdried over magnesium sulfate
9. concentrationconcentrated under reduced pressure
10. customto give a syrup
11. washeluted with a mixture of methanol and chloroform (2:98, V/V)