1: BuLi / diethyl ether / 1.) -80 to -30 deg C, 1.5 h, 2.) -60 deg C to r.t., 5 h 2: H2SO4, H2O / tetrahydrofuran / 0.42 h / Ambient temperature 3: HF, I2, H2O / acetonitrile / 48 h / Ambient temperature 4: 82 percent / 2,6-lutidine / CH2Cl2 5: 14 percent / CeCl3*7H2O, NaBH4 / methanol / 1.67 h / -60 - 0 °C 6: DMAP, pyridine / CH2Cl2 / 12 h / Ambient temperature 7: pyridine*HF / tetrahydrofuran / 1 h / Ambient temperature 8: Dess-Martin periodinane / 0.67 h / Ambient temperature 9: tetrahydrofuran / 1 h / -80 - -47 °C 10: Dess-Martin periodinane / CH2Cl2 / 0.42 h / Ambient temperature 11: pyridine, CSA / CH2Cl2 / 1 h / Ambient temperature 12: 88 percent / K2CO3 / methanol / 60 h / Ambient temperature 13: 90 percent / 2,6-lutidine / CH2Cl2 14: 1.) dicyclohexylmagnesium bromide / 1.) THF, -65 to -50 deg C, 35 min, 2.) THF, -65 to -50 deg C, 40 min 15: 93 percent / TBAF / tetrahydrofuran / 34 h / Ambient temperature 16: 3 Angstroem molecular sieves, TFA / CH2Cl2 / 0.6 h / Ambient temperature View Scheme