tetrabutyl ammonium fluoride in tetrahydrofuran T=0 - 25°C;

tetrabutyl ammonium fluoride in tetrahydrofuran 18 h; Ambient temperature;

potassium carbonate in methanol; water

1: pyridine / CH2Cl2 / Ambient temperature 2: NaI / acetone / 2 h / Heating 3: PPTS / CH2Cl2 / Ambient temperature 4: 1) bipyridyl, n-BuLi / 1) THF, hexane, -78 deg C, 1h, 2) HMPA, RT, 24h 5: 1) disiamylborane, 2) HOAc / 1) THF, 0 deg C, 1h, 2) RT, 4h 6: 71 percent / 3N HCl / methanol / 1.5 h / Ambient temperature 7: 88 percent / pyridine / acetonitrile / 1 h / 0 °C 8: 43 percent / t-BuOOH, D-(-)-DIPT, Ti(O-i-Pr)4, molecular sieves 4 Angstroem / CH2Cl2 / 16 h / -21 °C 9: t-BuOOH, Ti(O-i-Pr)4, L-(+)-DIPT, molecular sieves 4 Angstroem / CH2Cl2 / -21 °C 10: PPh3, diethyl azodicarboxylate / tetrahydrofuran / 1 h / 0 °C 11: 1N NaOH / methanol / 1 h / 0 °C 12: 1) Bu3SnLi, 2) I2 / 1) THF, 0 deg C, 3h, 2) Et2O, 0 deg C 13: imidazole / dimethylformamide / Ambient temperature 14: 1) disiamylborane, 2) LiOH / 2) Pd(PPh3)4 / 1) THF, 0 deg C, 1h, 2) 40 degC, 12h 15: 79 percent / n-Bu4NF / tetrahydrofuran / 18 h / Ambient temperature View Scheme

1: PPTS / CH2Cl2 / Ambient temperature 2: 1) bipyridyl, n-BuLi / 1) THF, hexane, -78 deg C, 1h, 2) HMPA, RT, 24h 3: 1) disiamylborane, 2) HOAc / 1) THF, 0 deg C, 1h, 2) RT, 4h 4: 71 percent / 3N HCl / methanol / 1.5 h / Ambient temperature 5: 88 percent / pyridine / acetonitrile / 1 h / 0 °C 6: 43 percent / t-BuOOH, D-(-)-DIPT, Ti(O-i-Pr)4, molecular sieves 4 Angstroem / CH2Cl2 / 16 h / -21 °C 7: t-BuOOH, Ti(O-i-Pr)4, L-(+)-DIPT, molecular sieves 4 Angstroem / CH2Cl2 / -21 °C 8: PPh3, diethyl azodicarboxylate / tetrahydrofuran / 1 h / 0 °C 9: 1N NaOH / methanol / 1 h / 0 °C 10: 1) Bu3SnLi, 2) I2 / 1) THF, 0 deg C, 3h, 2) Et2O, 0 deg C 11: imidazole / dimethylformamide / Ambient temperature 12: 1) disiamylborane, 2) LiOH / 2) Pd(PPh3)4 / 1) THF, 0 deg C, 1h, 2) 40 degC, 12h 13: 79 percent / n-Bu4NF / tetrahydrofuran / 18 h / Ambient temperature View Scheme

1: NaI / acetone / 2 h / Heating 2: PPTS / CH2Cl2 / Ambient temperature 3: 1) bipyridyl, n-BuLi / 1) THF, hexane, -78 deg C, 1h, 2) HMPA, RT, 24h 4: 1) disiamylborane, 2) HOAc / 1) THF, 0 deg C, 1h, 2) RT, 4h 5: 71 percent / 3N HCl / methanol / 1.5 h / Ambient temperature 6: 88 percent / pyridine / acetonitrile / 1 h / 0 °C 7: 43 percent / t-BuOOH, D-(-)-DIPT, Ti(O-i-Pr)4, molecular sieves 4 Angstroem / CH2Cl2 / 16 h / -21 °C 8: t-BuOOH, Ti(O-i-Pr)4, L-(+)-DIPT, molecular sieves 4 Angstroem / CH2Cl2 / -21 °C 9: PPh3, diethyl azodicarboxylate / tetrahydrofuran / 1 h / 0 °C 10: 1N NaOH / methanol / 1 h / 0 °C 11: 1) Bu3SnLi, 2) I2 / 1) THF, 0 deg C, 3h, 2) Et2O, 0 deg C 12: imidazole / dimethylformamide / Ambient temperature 13: 1) disiamylborane, 2) LiOH / 2) Pd(PPh3)4 / 1) THF, 0 deg C, 1h, 2) 40 degC, 12h 14: 79 percent / n-Bu4NF / tetrahydrofuran / 18 h / Ambient temperature View Scheme

1: 1) bipyridyl, n-BuLi / 1) THF, hexane, -78 deg C, 1h, 2) HMPA, RT, 24h 2: 1) disiamylborane, 2) HOAc / 1) THF, 0 deg C, 1h, 2) RT, 4h 3: 71 percent / 3N HCl / methanol / 1.5 h / Ambient temperature 4: 88 percent / pyridine / acetonitrile / 1 h / 0 °C 5: 43 percent / t-BuOOH, D-(-)-DIPT, Ti(O-i-Pr)4, molecular sieves 4 Angstroem / CH2Cl2 / 16 h / -21 °C 6: t-BuOOH, Ti(O-i-Pr)4, L-(+)-DIPT, molecular sieves 4 Angstroem / CH2Cl2 / -21 °C 7: PPh3, diethyl azodicarboxylate / tetrahydrofuran / 1 h / 0 °C 8: 1N NaOH / methanol / 1 h / 0 °C 9: 1) Bu3SnLi, 2) I2 / 1) THF, 0 deg C, 3h, 2) Et2O, 0 deg C 10: imidazole / dimethylformamide / Ambient temperature 11: 1) disiamylborane, 2) LiOH / 2) Pd(PPh3)4 / 1) THF, 0 deg C, 1h, 2) 40 degC, 12h 12: 79 percent / n-Bu4NF / tetrahydrofuran / 18 h / Ambient temperature View Scheme

1: 95 percent / PPTS / CH2Cl2 / 1 h / Ambient temperature 2: 1) bipyridyl, n-BuLi / 1) THF, hexane, -78 deg C, 1h, 2) HMPA, RT, 24h 3: 1) disiamylborane, 2) HOAc / 1) THF, 0 deg C, 1h, 2) RT, 4h 4: 71 percent / 3N HCl / methanol / 1.5 h / Ambient temperature 5: 88 percent / pyridine / acetonitrile / 1 h / 0 °C 6: 43 percent / t-BuOOH, D-(-)-DIPT, Ti(O-i-Pr)4, molecular sieves 4 Angstroem / CH2Cl2 / 16 h / -21 °C 7: t-BuOOH, Ti(O-i-Pr)4, L-(+)-DIPT, molecular sieves 4 Angstroem / CH2Cl2 / -21 °C 8: PPh3, diethyl azodicarboxylate / tetrahydrofuran / 1 h / 0 °C 9: 1N NaOH / methanol / 1 h / 0 °C 10: 1) Bu3SnLi, 2) I2 / 1) THF, 0 deg C, 3h, 2) Et2O, 0 deg C 11: imidazole / dimethylformamide / Ambient temperature 12: 1) disiamylborane, 2) LiOH / 2) Pd(PPh3)4 / 1) THF, 0 deg C, 1h, 2) 40 degC, 12h 13: 79 percent / n-Bu4NF / tetrahydrofuran / 18 h / Ambient temperature View Scheme

1: 88 percent / pyridine / acetonitrile / 1 h / 0 °C 2: 43 percent / t-BuOOH, D-(-)-DIPT, Ti(O-i-Pr)4, molecular sieves 4 Angstroem / CH2Cl2 / 16 h / -21 °C 3: t-BuOOH, Ti(O-i-Pr)4, L-(+)-DIPT, molecular sieves 4 Angstroem / CH2Cl2 / -21 °C 4: PPh3, diethyl azodicarboxylate / tetrahydrofuran / 1 h / 0 °C 5: 1N NaOH / methanol / 1 h / 0 °C 6: 1) Bu3SnLi, 2) I2 / 1) THF, 0 deg C, 3h, 2) Et2O, 0 deg C 7: imidazole / dimethylformamide / Ambient temperature 8: 1) disiamylborane, 2) LiOH / 2) Pd(PPh3)4 / 1) THF, 0 deg C, 1h, 2) 40 degC, 12h 9: 79 percent / n-Bu4NF / tetrahydrofuran / 18 h / Ambient temperature View Scheme

1: 1) bipyridyl, n-BuLi / 1) THF, hexane, -78 deg C, 1h, 2) HMPA, RT, 24h 2: 1) disiamylborane, 2) HOAc / 1) THF, 0 deg C, 1h, 2) RT, 4h 3: 71 percent / 3N HCl / methanol / 1.5 h / Ambient temperature 4: 88 percent / pyridine / acetonitrile / 1 h / 0 °C 5: 43 percent / t-BuOOH, D-(-)-DIPT, Ti(O-i-Pr)4, molecular sieves 4 Angstroem / CH2Cl2 / 16 h / -21 °C 6: t-BuOOH, Ti(O-i-Pr)4, L-(+)-DIPT, molecular sieves 4 Angstroem / CH2Cl2 / -21 °C 7: PPh3, diethyl azodicarboxylate / tetrahydrofuran / 1 h / 0 °C 8: 1N NaOH / methanol / 1 h / 0 °C 9: 1) Bu3SnLi, 2) I2 / 1) THF, 0 deg C, 3h, 2) Et2O, 0 deg C 10: imidazole / dimethylformamide / Ambient temperature 11: 1) disiamylborane, 2) LiOH / 2) Pd(PPh3)4 / 1) THF, 0 deg C, 1h, 2) 40 degC, 12h 12: 79 percent / n-Bu4NF / tetrahydrofuran / 18 h / Ambient temperature View Scheme