Реакция #554617

Уравнение реакции

NaHCO3

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

DMSO

acetic anhydride

→

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

Выход 71.0%

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

Выход 71.0%

Растворители

acetic acid

Условия реакции

Обработка

1. 1
   Экстракцияextracted with CH2Cl2 (3×100 mL)
2. 2
   ЭкстракцияThe combined organic extract
3. 3
   Промывкаwas then washed with a saturated NaHCO3 solution (100 mL)
4. 4
   Сушкаdried over Na2SO4
5. 5
   Концентрированиеconcentrated under vacuum
6. 6
   ДругоеThe resultant yellowish oil was then purified on silica gel column (Hex: EtOAc/1:1 to 1:4)

Методика

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.

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