1: 85 percent / sec-BuLi / tetrahydrofuran / 4.5 h / -78 - 20 °C 2: 76 percent / BF3*Et2O / 2 h / -78 - -20 °C 3: imidazole / dimethylformamide / 16 h / 40 °C 4: DDQ, H2O / CH2Cl2 / 1 h / 25 °C 5: Swern oxidation 6: 1.) n-BuLi / 1.) THF, -78 deg C, 0.5 h, 2.) THF, -78 deg C, 5 h 7: NaH / dimethylformamide / 6.5 h / 0 °C 8: OsO4, NaIO4 / tetrahydrofuran / 17 h / 25 °C / phosphate buffer pH 7 9: KN(SiMe3)2, 18-crown-6 / tetrahydrofuran / 4 h / -78 °C 10: DIBAL / toluene / 1 h / -78 °C 11: PDC / CH2Cl2 / 24 h / 25 °C 12: CH2Cl2 / 22 h / 40 °C 13: 1.) 0.02percent aq. HCl, 2.) aq. LiOH / 1.) MeOH, 25 deg C, 0.5 h, 2.) THF, MeOH, 25 deg C , 29 h 14: bis(2-oxo-3-oxazolidinyl)phosphinic chloride, i-Pr2NEt / toluene / 15 h / 85 °C 15: n-Bu4NF / tetrahydrofuran / 48 h / 25 °C 16: TFA / CH2Cl2 / 17 h / 25 °C 17: AgO, 1M HNO3 / dioxane / 2.5 h / 25 °C View Scheme