Реакция #1256738

Уравнение реакции

3′,5′-di-O-acetyl-2′-deoxyguanosine

triphenylphosphine

benzyl alcohol

diisopropylazodicarboxylate

→

3′,5′-Di-O-acetyl-O6-benzyl-2′-deoxyguanosine

Растворители

1,4-dioxane

Условия реакции

Обработка

1. 1
   Температураwas then cooled
2. 2
   Концентрированиеconcentrated to a thick paste on a rotary evaporator

Методика

3′,5′-Di-O-acetyl-O6-benzyl-2′-deoxyguanosine (4) was prepared following the method of Zajc et al., Tet. Lett. 1992, 33, 3409-3412. To a mixture of 3′,5′-di-O-acetyl-2′-deoxyguanosine (5.71 g, 16.3 mmol), triphenylphosphine (5.91 g, 22.5 mmol) and benzyl alcohol (2.5 mL, 24.1 mmol) in 100 mL 1,4-dioxane under argon was slowly added diisopropylazodicarboxylate (4.5 mL, 22.8 mmol). The mixture was heated to 85° C. for two hr and was then cooled and concentrated to a thick paste on a rotary evaporator. The product was isolated as a light brown solid (1.78 g, 24.8%) following silica gel column chromatography with 10% ethyl acetate/chloroform. 1H-NMRδH(DMSO-d6) 8.09 (s, 1H, H-8), 7.51-7.35 (m, 5H, Ar), 6.54 (s, 2H, N2H2, exchange with D2O), 6.24 (dd, J=6.0, J′=8.5, 1H, H-1′), 5.50 (s, 2H, OCH2Ar), 5.33-5.32 (m, 1H, H-3′), 4.32-4.27 (m, 1H, H-4′), 4.22-4.18 (m, 2H, H-5′), 3.06-2.98 (m, 1H, H-2′α), 2.50-2.44 (m, 1H, H-2′β), 2.09 (s, 3H, COCH3), 2.02 (s, 3H, COCH3); MS, m/z 442.1 [M+H]+, 464.1 [M+Na]+; Anal. Calcd. for C21H23N5O6: C, 57.14; H, 5.25; N, 15.86.

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