1: 90 percent / NaI, Bu3SnH, AIBN / 1,2-dimethoxy-ethane / 7.5 h / 80 °C 2: Et3N / CH2Cl2 / 0.5 h 3: 56 percent / Ag2CO3 / acetone; H2O / 27 h / Heating 4: 82 percent / 2,6-lutidine / CH2Cl2 / 3.25 h / -50 - 0 °C 5: BuLi / diethyl ether / 1.) -80 to -30 deg C, 1.5 h, 2.) -60 deg C to r.t., 5 h 6: H2SO4, H2O / tetrahydrofuran / 0.42 h / Ambient temperature 7: HF, I2, H2O / acetonitrile / 48 h / Ambient temperature 8: 82 percent / 2,6-lutidine / CH2Cl2 9: 14 percent / CeCl3*7H2O, NaBH4 / methanol / 1.67 h / -60 - 0 °C 10: DMAP, pyridine / CH2Cl2 / 12 h / Ambient temperature 11: pyridine*HF / tetrahydrofuran / 1 h / Ambient temperature 12: Dess-Martin periodinane / 0.67 h / Ambient temperature 13: tetrahydrofuran / 1 h / -80 - -47 °C 14: Dess-Martin periodinane / CH2Cl2 / 0.42 h / Ambient temperature 15: pyridine, CSA / CH2Cl2 / 1 h / Ambient temperature 16: 88 percent / K2CO3 / methanol / 60 h / Ambient temperature 17: 90 percent / 2,6-lutidine / CH2Cl2 18: 1.) dicyclohexylmagnesium bromide / 1.) THF, -65 to -50 deg C, 35 min, 2.) THF, -65 to -50 deg C, 40 min 19: 93 percent / TBAF / tetrahydrofuran / 34 h / Ambient temperature 20: 3 Angstroem molecular sieves, TFA / CH2Cl2 / 0.6 h / Ambient temperature View Scheme