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

1: 1.) dicyclohexylmagnesium bromide / 1.) THF, -65 to -50 deg C, 35 min, 2.) THF, -65 to -50 deg C, 40 min 2: 93 percent / TBAF / tetrahydrofuran / 34 h / Ambient temperature 3: 3 Angstroem molecular sieves, TFA / CH2Cl2 / 0.6 h / Ambient temperature View Scheme

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

1: t-BuOK, 18-crown-6 / pentane / 2.5 h / Ambient temperature 2: BuLi / diethyl ether / 1.) -80 to -30 deg C, 1.5 h, 2.) -60 deg C to r.t., 5 h 3: H2SO4, H2O / tetrahydrofuran / 0.42 h / Ambient temperature 4: HF, I2, H2O / acetonitrile / 48 h / Ambient temperature 5: 82 percent / 2,6-lutidine / CH2Cl2 6: 14 percent / CeCl3*7H2O, NaBH4 / methanol / 1.67 h / -60 - 0 °C 7: DMAP, pyridine / CH2Cl2 / 12 h / Ambient temperature 8: pyridine*HF / tetrahydrofuran / 1 h / Ambient temperature 9: Dess-Martin periodinane / 0.67 h / Ambient temperature 10: tetrahydrofuran / 1 h / -80 - -47 °C 11: Dess-Martin periodinane / CH2Cl2 / 0.42 h / Ambient temperature 12: pyridine, CSA / CH2Cl2 / 1 h / Ambient temperature 13: 88 percent / K2CO3 / methanol / 60 h / Ambient temperature 14: 90 percent / 2,6-lutidine / CH2Cl2 15: 1.) dicyclohexylmagnesium bromide / 1.) THF, -65 to -50 deg C, 35 min, 2.) THF, -65 to -50 deg C, 40 min 16: 93 percent / TBAF / tetrahydrofuran / 34 h / Ambient temperature 17: 3 Angstroem molecular sieves, TFA / CH2Cl2 / 0.6 h / Ambient temperature View Scheme

1: 92 percent / Et3N / CH2Cl2 / 41 h / Ambient temperature 2: 90 percent / NaI, Bu3SnH, AIBN / 1,2-dimethoxy-ethane / 7.5 h / 80 °C 3: Et3N / CH2Cl2 / 0.5 h 4: 56 percent / Ag2CO3 / acetone; H2O / 27 h / Heating 5: 82 percent / 2,6-lutidine / CH2Cl2 / 3.25 h / -50 - 0 °C 6: BuLi / diethyl ether / 1.) -80 to -30 deg C, 1.5 h, 2.) -60 deg C to r.t., 5 h 7: H2SO4, H2O / tetrahydrofuran / 0.42 h / Ambient temperature 8: HF, I2, H2O / acetonitrile / 48 h / Ambient temperature 9: 82 percent / 2,6-lutidine / CH2Cl2 10: 14 percent / CeCl3*7H2O, NaBH4 / methanol / 1.67 h / -60 - 0 °C 11: DMAP, pyridine / CH2Cl2 / 12 h / Ambient temperature 12: pyridine*HF / tetrahydrofuran / 1 h / Ambient temperature 13: Dess-Martin periodinane / 0.67 h / Ambient temperature 14: tetrahydrofuran / 1 h / -80 - -47 °C 15: Dess-Martin periodinane / CH2Cl2 / 0.42 h / Ambient temperature 16: pyridine, CSA / CH2Cl2 / 1 h / Ambient temperature 17: 88 percent / K2CO3 / methanol / 60 h / Ambient temperature 18: 90 percent / 2,6-lutidine / CH2Cl2 19: 1.) dicyclohexylmagnesium bromide / 1.) THF, -65 to -50 deg C, 35 min, 2.) THF, -65 to -50 deg C, 40 min 20: 93 percent / TBAF / tetrahydrofuran / 34 h / Ambient temperature 21: 3 Angstroem molecular sieves, TFA / CH2Cl2 / 0.6 h / Ambient temperature View Scheme

1: BuLi / diethyl ether / 1.) -30 deg C, 30 min, 2.) -50 to 0 deg C, 1 h 2: BF3*Et2O / 2 h / Ambient temperature 3: t-BuOK, 18-crown-6 / pentane / 2.5 h / Ambient temperature 4: BuLi / diethyl ether / 1.) -80 to -30 deg C, 1.5 h, 2.) -60 deg C to r.t., 5 h 5: H2SO4, H2O / tetrahydrofuran / 0.42 h / Ambient temperature 6: HF, I2, H2O / acetonitrile / 48 h / Ambient temperature 7: 82 percent / 2,6-lutidine / CH2Cl2 8: 14 percent / CeCl3*7H2O, NaBH4 / methanol / 1.67 h / -60 - 0 °C 9: DMAP, pyridine / CH2Cl2 / 12 h / Ambient temperature 10: pyridine*HF / tetrahydrofuran / 1 h / Ambient temperature 11: Dess-Martin periodinane / 0.67 h / Ambient temperature 12: tetrahydrofuran / 1 h / -80 - -47 °C 13: Dess-Martin periodinane / CH2Cl2 / 0.42 h / Ambient temperature 14: pyridine, CSA / CH2Cl2 / 1 h / Ambient temperature 15: 88 percent / K2CO3 / methanol / 60 h / Ambient temperature 16: 90 percent / 2,6-lutidine / CH2Cl2 17: 1.) dicyclohexylmagnesium bromide / 1.) THF, -65 to -50 deg C, 35 min, 2.) THF, -65 to -50 deg C, 40 min 18: 93 percent / TBAF / tetrahydrofuran / 34 h / Ambient temperature 19: 3 Angstroem molecular sieves, TFA / CH2Cl2 / 0.6 h / Ambient temperature View Scheme

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

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

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

1: 93 percent / TBAF / tetrahydrofuran / 34 h / Ambient temperature 2: 3 Angstroem molecular sieves, TFA / CH2Cl2 / 0.6 h / Ambient temperature View Scheme