反応 #6876

反応方程式

dichloromethane

sodium hydrogen carbonate

nucleoside

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

sodium hydride

→

nucleoside

収率 96.0%

(1R,3R,4R,7R)-7-Benzyloxy-1-(4,4′-dimethoxytrityloxymethyl)-3-(thymin-1-yl)-2,5-dioxabicyclo[2.2.1]heptane

収率 96.0%

溶媒

dichloromethane pyridine

DMF

反応条件

後処理

1. 1
   温度cooled to 0° C.
2. 2
   洗浄The combined organic phase was washed with saturated aqueous solutions of sodium hydrogen carbonate (60 cm3×3) and brine (40 cm3×3)
3. 3
   乾燥dried (Na2SO4)
4. 4
   その他evaporated to dryness under reduced pressure
5. 5
   その他The residue was purified by silica gel column chromatography

実験手順

To a solution of nucleoside 7 (4.22 g, 5.06 mmol) in anhydrous DMF (25 cm3) at 0° C. was added a 60% suspension of sodium hydride in mineral oil (w/w, 0.607 g, 1 5.7 mmol, added in four portions during 20 min) and the reaction mixture was stirred at room temperature for 25 h, cooled to 0° C. and diluted with dichloromethane/pyridine (100 cm3, 99.5:0.5, v/v). A saturated aqueous solution of sodium hydrogen carbonate (120 cm3) was added whereupon extraction was performed using dichloromethane (75 cm3×2). The combined organic phase was washed with saturated aqueous solutions of sodium hydrogen carbonate (60 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 (0.5–1.5% methanol; 0.5% pyridine, v/v/v) as eluent yielding nucleoside 8 (3.2 g, 96%) as a white solid material after evaporation of the solvents under reduced pressure.

出典