反应 #630098

反应方程式

pyridine

acetone

D-galactose

antimony pentachloride

→

1,2:3,4-di-O-isopropylidene-α-D-galactopyranose

收率 82.9%

反应条件

后处理

1. 1
   温度the mixture was refluxed
2. 2
   其他During this reaction
3. 3
   干燥the refluxing solvent was dried with 20 g of Molecular Sieves 3A
4. 4
   其他After completion of the reaction
5. 5
   workup.DISTILLATIONthe acetone was distilled off under reduced pressure
6. 6
   workup.DISSOLUTIONThe residue was dissolved in benzene
7. 7
   洗涤the solution was washed with aqueous sodium bicarbonate and water
8. 8
   干燥dried over anhydrous magnesium sulfate
9. 9
   workup.DISTILLATIONThe benzene was distilled off
10. 10
    workup.DISTILLATIONthe resulting residue was distilled under reduced pressure

实验过程

To 200 ml of acetone were added 10.0 g of D-galactose and 89.7 mg of antimony pentachloride, and the mixture was refluxed with stirring in a water bath of 60° C. for 8 hours. During this reaction, the refluxing solvent was dried with 20 g of Molecular Sieves 3A interposed between the reaction vessel and the condenser. After completion of the reaction, a small amount of pyridine was added to the reaction mixture, and the acetone was distilled off under reduced pressure. The residue was dissolved in benzene, and the solution was washed with aqueous sodium bicarbonate and water, and dried over anhydrous magnesium sulfate. The benzene was distilled off, and the resulting residue was distilled under reduced pressure to give 11.97 g (82.9%) of 1,2:3,4-di-O-isopropylidene-α-D-galactopyranose as a fraction having a boiling point of 129°-133° C./0.2 mmHg.

来源