Figure 9: Synthesis of heneicosafuranosyl arabinogalactan (1).

Reagents and conditions: (a) Py·HF, THF:Py (5:1), 0 °C→25 °C, 4 h, 85%. (b) AuCl3 (7 mol%), AgOTf (7 mol%), CH2Cl2, 4 Å MS powder, 25 °C, 24 h, 71%. (c) 0.5M NaOMe, MeOH, CH2Cl2, 4 h, 25 °C, 74%.