1: 48 percent / titanium(IV)isopropoxide / tetrahydrofuran / 1.5 h / Ambient temperature 2: 98 percent / 1.) pyridine, OsO4, 2.) H2S / 1.) THF, rt, overnight, 2.) MeOH, 30 min 3: 96 percent / amberlyst-15 resin / methanol / 48 h / Ambient temperature View Scheme

1: Et3N, DMAP / CH2Cl2 2: 85 percent / copper(I) iodide / tetrahydrofuran / -10 °C 3: 94 percent / pyridine / CH2Cl2 / Ambient temperature 4: NaN3 / dimethylformamide / 7 h / 80 °C 5: 2N aq. HCl / 0.5 h 6: 95 percent / OsO4, K3Fe(CN)6, K2CO3, DHQ-CLB, water / 2-methyl-propan-2-ol 7: 89 percent / imidazole / dimethylformamide / 0 °C 8: pyridine / CH2Cl2 / 2 h / Ambient temperature 9: pyridine / 4 h / Ambient temperature 10: 91 percent / n-Bu4NF / tetrahydrofuran / 1 h / 0 °C 11: 90 percent / lithium bromide / acetic acid; tetrahydrofuran / 24 h / Ambient temperature 12: NaOAc / methanol / 10 h / Heating View Scheme