反应详情

4′-C-Aminomethylthymidine (4) (1.5 mmol) was dissolved in methanol (10 mL) and triethylamine (1.5 mL) at ambient temperature. The solution was then treated with neat ethyl trifluoroacetate (1 mL) and the resulting solution stirred for 18 hours at ambient temperature with exclusion of moisture. The solvents and reagents were then removed under vacuum to give the crude product. Purification by flash column chromatography (9:1 dichloromethane:methanol) afforded the title compound (7) as a white foam (0.37 g, 66%). δH(300 MHz, CD3OD) 8.77(1H, t, br, N3—H), 7.73(1H, s, H-6), 6.24(1H, dd, H-1′), 4.56(1H, dd, H-3′), 3.6(3H, s, H-5′, obs d, 4′-C—CH2), 3.53(1H, d, 4′-C—CH2), 2.35(2H, m, H-2′), 1.81(3H, s, 5-CH3); δC(75.45 MHz, CD3OD), 166.24, 160.08–158.62(q, CF3CO), 152.21, 138.11, 123.01–111.51(q, CF3CO), 111.51, 88.93, 85.69, 72.79, 64.23, 41.70, 40.81, 12.40; ES +ve m/z 368 (M+H)+, 390(M+Na)+; ν cm−1 1684. For an alternative synthesis of this compound see Wang et al, Tetrahedron Letters 1996, 37, 6515–6518.

1. customat ambient temperature
2. customThe solvents and reagents were then removed under vacuum
3. customto give the crude product
4. customPurification by flash column chromatography (9:1 dichloromethane:methanol)