反応 #1994272

反応方程式

( 2 )

5′-O-(tert-butyidimethylsilyl)-5-[3-(2,2,2-trifluoroacetamido)-prop-1-ynyl]-2′-deoxyuridine

acetic acid

acetic anhydride

DMSO

→

oil

収率 89.0%

5′-O-(tert-Butydimethylsilyl)-3′-O-methylthiomethyl-5-[3-(2,2,2-trifluoroacetamido)-prop-1-ynyl]-2′-deoxyuridine

収率 89.0%

反応条件

後処理

1. 1
   その他was quenched with sat. aq. NaHCO3
2. 2
   workup.ADDITIONEtOAc (50 ml) was added
3. 3
   抽出the aqueous layer was extracted three times with ethyl acetate
4. 4
   洗浄The combined organic layers were washed with sat. aq. NaHCO3 solution
5. 5
   乾燥dried (MgSO4)
6. 6
   その他After removing the solvent under reduced pressure
7. 7
   その他the product (3) was purified by chromatography on silica (EtOAc: petroleum ether 8:2)

実験手順

To a solution of (2) (1.84 g, 3.7 mmol) in dry DMSO (7 ml) was added acetic acid (3.2 ml) and acetic anhydride (10.2 ml). The mixture was stirred for 2 days at room temperature, before it was quenched with sat. aq. NaHCO3. EtOAc (50 ml) was added and the aqueous layer was extracted three times with ethyl acetate. The combined organic layers were washed with sat. aq. NaHCO3 solution and dried (MgSO4). After removing the solvent under reduced pressure, the product (3) was purified by chromatography on silica (EtOAc: petroleum ether 8:2) yielding a clear sticky oil (1.83 g, 89%). 1H NMR (d6 DMSO): δ 0.00 (s, 6H, CH3), 0.79 (s, 9H, tBu), 1.96-2.06 (m, 1H, H-2′), 1.99 (s, 3H, SCH3), 2.20-2.26 (m, 1H, H-2′), 3.63-3.74 (m, 2H, H-5′), 3.92-3.95 (m, 1H, H-4′), 4.11-4.13 (m, 2H, CH2), 4.28-4.30 (m, 1H, H-3′), 4.59 (br s, 2H, CH2), 5.97 (t, J=6.9 Hz, 1H, H-1′), 7.85 (s, 1H, H-6), 9.95 (t, J=5.3 Hz, 1H, NH), 11.64 (s, 1H, NH). Mass (−ve electrospray) calcd for C22H32F3N3O6SSi 551.17. Found 550.

出典