Figure 4: Synthesis of Galactofuranoside-building blocks.

Reagents and conditions: (a) Br2, CH2Cl2, 4 Å MS, 0 °C, 15 min. (b) Propargyl alcohol, 2,6-lutidine CH2Cl2, 4 Å MS 0 °C→25 °C, 10 h, 81% over two steps. (c) Methyl 4-hydroxybutanoate, AuCl3, 4 Å MS, CH2Cl2, 25 °C, 2 h, 80%. (d) NaOMe, MeOH, 25 °C, 15 h. (e) 2-Methoxypropene, acetone, PTSA, 8 h. (f) BzCl, py., 0→25 °C. (g) PTSA, MeOH, 25 °C, 4 h, 70% over four steps.