反応 #6875

反応方程式

4,4′-dimethoxytrityl chloride

nucleoside

1-(3-O-Benzyl-4-C-(p-Toluenesulphonyloxymethyl)β-D-xylofuranosyl)thymine

4,4′-dimethoxytrityl chloride

→

nucleoside

収率 75.0%

1-(3-O-Benzyl-5-O-(4,4′-dimethoxytrityl)-4-C-(p-toluenesulphonyloxymethyl)-β-D-xylofuranosyl)thymine

収率 75.0%

溶媒

dichloromethane

pyridine

反応条件

後処理

1. 1
   workup.STIRRINGstirring
2. 2
   workup.WAITwas continued for 36 h at room temperature
3. 3
   その他The organic phase was separated
4. 4
   洗浄washed with saturated aqueous solutions of sodium hydrogen carbonate (25 cm3×3) and brine (40 cm3×3)
5. 5
   乾燥dried (Na2SO4)
6. 6
   その他evaporated to dryness under reduced pressure
7. 7
   その他The residue was purified by silica gel column chromatography

実験手順

To a solution of nucleoside 6 (3.66 g, 6.88 mmol) in anhydrous pyridine (25 cm3) was added N,N-(dimethylamino)pyridine (0.84 g, 6.81 mmol) and 4,4′-dimethoxytrityl chloride (3.5 g, 13.2 mmol) and the mixture was stirred for 23 h at room temperature. Additional N,N-(dimethylamino)pyridine (0.250 g, 2.06 mmol) and 4,4′-dimethoxytrityl chloride (0.700 g, 2.06 mmol) was added, and stirring was continued for 36 h at room temperature. Ice cold H2O (50 cm3) was added and the reaction mixture was diluted with dichloromethane (150 cm3). The organic phase was separated and washed with saturated aqueous solutions of sodium hydrogen carbonate (25 cm3×3) and brine (40 cm3×3), dried (Na2SO4) and evaporated to dryness under reduced pressure. The residue was purified by silica gel column chromatography using dichloromethane/methanol/pyridine (0.75–1.5% methanol; 0.5% pyridine, v/v/v) as eluent to afford nucleoside 7 (4.28 g, 75%) as a white solid material after evaporation of the solvents under reduced pressure.

出典