dinucleosides containing the N-arylsulfonamide motif.
Scheme 2 Synthesis of dinucleosides 1–9. (a) K2CO3, KI, DMF, 50 °C, 24 h, 74%; (b) PhSH, K2CO3, DMF, 25 °C, 2 h, 76%; (c) TFA/H2O 8/2, 25 °C, 3 h, 76% for 1 and 34% for 9; (d) (i) 21, AcOH, CH2Cl2, 25 °C, 2 h, (ii) NaBH(OAc)3, 25 °C, 2 h, 93%; (e) (i) TFA/H2O 8/2, 25 °C, 3 h, (ii) 2 M aqueous solution LiOH, 25 °C, 0.5 h, 32%; (f) TFA/H2O 8/2, 25 °C, 3 h, 35%; (g) (i) TFA/H2O 8/