Figure 8: Synthesis of tridecaoligofuranoside.

Reagents and conditions: (a) AuCl3 (7 mol%), AgOTf (7 mol%), CH2Cl2, 4 Å MS powder, 25 °C, 24 h, 70% for 30 and 65% for 31. (b) Py·HF, THF:Py (5:1), 0 °C→25 °C, 4 h, 85% (c) NIS (3 eq.), TfOH (0.3 eq.), 4 days, 0 °C→25 °C, 24%.