Acetonitrile → 5'-O-Benzoyl-2',3'-didehydro-3'-deoxy-4'-ethynylthymidine

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

To an CH3CN (4 mL) solution of 5 (101.9 mg, 0.18 mmol) was added DBN (67 μL, 0.54 mmol) at 0° C. under Ar atmosphere, and the mixture was stirred at 80° C. for 9 h. The reaction mixture was neutralized by adding AcOH, and partitioned between CHCl3/sat. aqueous NaHCO3. Silica gel column chromatography (1.5% MeOH in CH2Cl2) of the organic layer gave 6 (60 mg, 95%) as solid: 1H NMR (CDCl3) δ1.42 (3H, d, JMe,6=1.2 Hz, Me-5), 2.70 (1H, s, C□CH),), 4.59 (1H, d, J5′a,5′b=12.0 Hz, H-5′a), 4.76 (1H, d, J5′,5′b=12.0 Hz, H-5′b), 5.99 (1H, dd, J1′,2′=1.2, J2′,3′=5.9, H-2′), 6.38 (1H, dd, J1′,3′=2.0 and J2′,3′=5.9 Hz, H-3′), 6.98 (1H, d, JMe,6=1.2 Hz), 7.12 (1H, m, H-1′), 7.45-7.49, 7.60-7.63 and 8.00-8.03 (5H, each as m, Ph), 8.37 (1H, br); FAB-MS (m/z) 353 (M++H).

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