Reaction #1365697

Reaction equation

Ascorbic acid

cesium carbonate

benzyl bromide

→

3-O-benzyl ascorbic acid

Yield 48.0%

Solvents

dimethylsulfoxide

dichloromethane

Conditions

Workup

1. 1
   TemperatureThe reaction mixture was cooled down to the room temperature
2. 2
   Otherto produce a solid
3. 3
   FiltrationAfter filtration
4. 4
   Concentrationthe filtrate was concentrated under reduced pressure
5. 5
   Otherpurified by column chromatography on silica gel

Procedure

Ascorbic acid (10 g, 56.8 mmol) was dissolved in 60 ml of dimethylsulfoxide, followed by addition of cesium carbonate (9.25 g, 28.4 mmol). After 20 minutes, benzyl bromide (6.75 ml, 56.8 mmol) was added to the reaction mixture and heated to 50° C. for 18 hours. The reaction mixture was cooled down to the room temperature and diluted with 150 ml of dichloromethane to produce a solid. After filtration, the filtrate was concentrated under reduced pressure and purified by column chromatography on silica gel to give 7.2 g of the 3-O-benzyl ascorbic acid (yield 48%).

Source