Reaction #6881

Reaction equation

nucleoside

1-(3,5-di-O-benzyl-β-D-allofuranosyl)thymine

p-toluenesulphonyl chloride

→

nucleoside

1-(3,5-di-O-benzyl-2,6-di-O-(p-toluenesulphonyl)-β-D-allofuranosyl)thymine

Solvents

dichloromethane

Conditions

Workup

1. 1
   Extractionextraction
2. 2
   DryingThe combined organic phase was dried (Na2SO4)
3. 3
   Otherevaporated to dryness under reduced pressure
4. 4
   OtherThe residue was purified by silica gel column chromatography

Procedure

To a stirred solution of nucleoside 16 (0.60 g, 1.28 mmol) in dichloromethane (70 cm3) at room temperature was added 4—N,N-(dimethylamino)pyridine (0.63g, 5.12 mmol) and p-toluenesulphonyl chloride (0.73 g, 3.84 mmol). After stirring for 3 h, ice-cold H2O (50 cm3) was added and extraction was performed using dichloromethane (3×75 cm3). The combined organic phase was dried (Na2SO4) and evaporated to dryness under reduced pressure. The residue was purified by silica gel column chromatography using dichloromethane/methanol (99.5:0.5, v/v) as eluent to give nucleoside 17 as white solid material (0.71 g, 71%) after evaporation of the solvents under reduced pressure.

Source