反応 #554617

反応方程式

NaHCO3

N6-Benzoyl-5′-O-tert-butyldimethylsilyl-2′-deoxyadenosine

DMSO

acetic anhydride

→

N6-benzoyl-3′-O -(methylthiomethyl)-5′-O-(tert-butyldimethylsilyl)-2′-deoxyadenosine

収率 71.0%

N6-Benzoyl-3′-O-(methylthiomethyl)-5′-O-(tert-butyldimethylsilyl)-2′-deoxyadenosine

収率 71.0%

溶媒

acetic acid

反応条件

後処理

1. 1
   抽出extracted with CH2Cl2 (3×100 mL)
2. 2
   抽出The combined organic extract
3. 3
   洗浄was then washed with a saturated NaHCO3 solution (100 mL)
4. 4
   乾燥dried over Na2SO4
5. 5
   濃縮concentrated under vacuum
6. 6
   その他The resultant yellowish oil was then purified on silica gel column (Hex: EtOAc/1:1 to 1:4)

実験手順

3.0 g N6-Benzoyl-5′-O-tert-butyldimethylsilyl-2′-deoxyadenosine (5a) (6.38 mmol) was dissolved in a mixture consisting of 11.96 mL DMSO, 5.46 mL acetic acid, and 17.55 mL acetic anhydride and stirred at room temperature for 48 h. The reaction mixture was then neutralized treating with a sufficient amount of saturated NaHCO3 solution and extracted with CH2Cl2 (3×100 mL). The combined organic extract was then washed with a saturated NaHCO3 solution (100 mL), dried over Na2SO4, and concentrated under vacuum. The resultant yellowish oil was then purified on silica gel column (Hex: EtOAc/1:1 to 1:4) to obtain the product N6-benzoyl-3′-O -(methylthiomethyl)-5′-O-(tert-butyldimethylsilyl)-2′-deoxyadenosine (6a) as white powder in 71% yield (2.4 g, Rf 0.6, EtOAc: hex/7:3). HR-MS: obs. m/z 530.2273, calcd. for C25H36O4N5SiS 530.2257 [M+H]+. 1H-NMR (CDCl3): δH 9.00 (s, 1H), 8.83 (s, 1H), 8.35 (s, 1H), 8.05 (d, J=7.6 Hz, 2H), 7.62 (m, 1H), 7.55 (m, 2H), 6.55 (t, J=7.19 Hz, 1H), 4.73 (m, 2H), 4.68 (m, 1H), 4.24 (m, 1H), 3.88 (dd, J=11.19, 3.19 Hz, 1H), 2.74-2.66 (m, 2H), 2.35 (s, 3H), 0.94 (s, 9H) and 0.13 (s, 6H) ppm.

出典