1: t-BuCOOH / 140 °C 2: PPTS / ethanol / Heating 3: LDA / tetrahydrofuran / -78 °C 4: 1.) DIBAL / 1.) CH2Cl2, -78 deg C 2.) glyme, room temp. 5: imidazole / dimethylformamide / Ambient temperature 6: pyridinium chlorochromate / CH2Cl2 / Ambient temperature 7: p-TsOH / methanol / Heating 8: 72 h / 170 °C 9: 1.) 1N HCl 2.) 5percent H2SO4 / 1.) Et2O, room temp. 2.) reflux 10: osmium tetroxide / pyridine / 0 °C / epimers ratio 8:7 11: lead tetracetate / tetrahydrofuran / 0 °C 12: CrO3, H2SO4 / acetone / 0 °C 13: OsO4, NaIO4 / tetrahydrofuran; H2O / 0 °C 14: diethyl ether / Ambient temperature 15: 1.) NaBCNH3 / 1.) MeOH, room temp. 2.) toluene, reflux 16: 1.) POCl3 2.) NaBH4 / 1.) benzene, reflux 2.) MeOH, 0 deg C View Scheme