反应详情

The mixture of 80 ml of acetone, 16 g of L-ascorbic acid and 18.8 ml of 2,2-dimethoxypropane was stirred for 15 minutes at room temperature. Hydrogen chloride was added slowly through bubbler to the reaction mixture over 5 minutes and the mixture was stirred for 1 hr at room temperature. Half volume of acetone was evaporated off under reduced pressure. The mixture was cooled in an ice bath, and the resulting precipitates were filtered and washed with 30 ml of cold acetone to give 15.2 g of 5,6-O-isopropylidene-L-ascorbic acid. Then mother liquor was concentrated to give 3.8 g of 5,6-O-isopropylidene-L-ascorbic acid.

1. stirringthe mixture was stirred for 1 hr at room temperature
2. customHalf volume of acetone was evaporated off under reduced pressure
3. temperatureThe mixture was cooled in an ice bath
4. customthe resulting precipitates
5. filtrationwere filtered
6. washwashed with 30 ml of cold acetone