zinc; titanium tetrachloride in tetrahydrofuran 0.5 h; Ambient temperature;

1: H(1+) 2: 82 percent / TBHP, Ti(O-iPr)4 3: 1.) n-Bu3SnLi, 2.) I2 / 2.) Et2O 5: n-PrNH2 / Pd(PPh3)4, CuI 6: 1.) (Sia)2BH, AcOH; 2.) H2O2, NaOH / 1.) THF 7: n-Bu4NF 8: 79 percent / LiOH View Scheme

1: 95 percent / PPTS / CH2Cl2 / 1 h / Ambient temperature 2: 1) n-BuLi / 1) THF, hexane, -60 deg C, 1h, 2) HMPA, RT, 36h 3: 3N HCl / methanol / 0.33 h / Ambient temperature 4: 41 percent / t-BuOOH, Ti(O-i-Pr)4, L-(+)-DIPT, molecular sieves 4 Angstroem / CH2Cl2 / 4 h / -21 °C 6: 97 percent / imidazole / dimethylformamide 7: 1) disiamylborane, 2) 2N LiOH / 2) Pd(PPh3)4 / 1) THF, 0 deg C, 1h 8: 55 percent / n-Bu4NF / tetrahydrofuran / 12 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