1: 88.6 percent / Ni(PPh3)2 / tetrahydrofuran / 4 h / 20 °C 2: 92.9 percent / n-BuLi / tetrahydrofuran; hexane / 3.5 h / 0 °C 3: 94 percent / Co(salen); O2 / dimethylformamide; toluene / 24 h / 20 °C View Scheme

1.1: 85 percent / dimethylformamide / 24 h / 20 °C 2.1: BuLi / hexane; tetrahydrofuran; hexamethylphosphoric acid triamide / 0.5 h / -70 °C 2.2: 75.8 percent / hexane; tetrahydrofuran; hexamethylphosphoric acid triamide / 3 h / -70 - 20 °C 3.1: EtNH2; Li / tetrahydrofuran / 0.5 h / -78 °C 3.2: 86.1 percent / isoprene; NH4Cl / tetrahydrofuran 4.1: 93 percent / aq. HCl / methanol; hexane / 4 h / 40 °C View Scheme

1.1: 96.8 percent / MsCl; 2,6-dimethylpyridine; LiCl / dimethylformamide / 4 h / -5 °C 2.1: BuLi / hexane; tetrahydrofuran; hexamethylphosphoric acid triamide / 0.5 h / -70 °C 2.2: 75.8 percent / hexane; tetrahydrofuran; hexamethylphosphoric acid triamide / 3 h / -70 - 20 °C 3.1: EtNH2; Li / tetrahydrofuran / 0.5 h / -78 °C 3.2: 86.1 percent / isoprene; NH4Cl / tetrahydrofuran 4.1: 93 percent / aq. HCl / methanol; hexane / 4 h / 40 °C View Scheme

1.1: phosphorous tribromide 2.1: 85 percent / dimethylformamide / 24 h / 20 °C 3.1: BuLi / hexane; tetrahydrofuran; hexamethylphosphoric acid triamide / 0.5 h / -70 °C 3.2: 75.8 percent / hexane; tetrahydrofuran; hexamethylphosphoric acid triamide / 3 h / -70 - 20 °C 4.1: EtNH2; Li / tetrahydrofuran / 0.5 h / -78 °C 4.2: 86.1 percent / isoprene; NH4Cl / tetrahydrofuran 5.1: 93 percent / aq. HCl / methanol; hexane / 4 h / 40 °C View Scheme

1: 85.3 percent / t-BuOK / tetrahydrofuran; dimethylformamide / 2.5 h / -40 - 20 °C 2: 77 percent / naphthalenyllithium / tetrahydrofuran / 2 h / -78 °C View Scheme

1: 92.9 percent / n-BuLi / tetrahydrofuran; hexane / 3.5 h / 0 °C 2: 94 percent / Co(salen); O2 / dimethylformamide; toluene / 24 h / 20 °C View Scheme

1.1: t-BuLi / diethyl ether; pentane / 0.5 h / -78 °C 1.2: ZnBr2 / tetrahydrofuran; diethyl ether; pentane / -78 - 0 °C 1.3: 91 percent / Cl2Pd(dppf)(CH2Cl2) / tetrahydrofuran; diethyl ether; pentane / 2 h / 23 °C 2.1: t-BuLi / diethyl ether; pentane / 0.5 h / -78 °C 2.2: ZnBr2 / tetrahydrofuran; diethyl ether / -78 - 0 °C 2.3: 90 percent / Cl2Pd(dppf)(CH2Cl2) / tetrahydrofuran; diethyl ether; pentane / 23 °C 3.1: t-BuLi / diethyl ether; pentane / 0.5 h / -78 °C 3.2: ZnBr2 / tetrahydrofuran; diethyl ether / -78 - 0 °C 3.3: 79 percent / Cl2Pd(dppf)(CH2Cl2) / tetrahydrofuran; pentane; diethyl ether / 23 °C 4.1: t-BuLi / diethyl ether; pentane / 0.5 h / -78 °C 4.2: ZnBr2 / tetrahydrofuran; diethyl ether / -78 - 0 °C 4.3: 83 percent / Cl2Pd(dppf)(CH2Cl2) / tetrahydrofuran; diethyl ether; pentane / 23 °C 5.1: 81 percent / KOH; H2O / methanol / 2 h / Heating 6.1: Cl2ZrCp2 / 1,2-dichloro-ethane / 8 h / 23 °C 6.2: 88 percent / I2 / tetrahydrofuran; 1,2-dichloro-ethane / 0.25 h / 0 °C 7.1: t-BuLi / diethyl ether; pentane / -78 °C 7.2: ZnBr2 / diethyl ether; tetrahydrofuran / -78 - 0 °C 7.3: Cl2Pd(dppf)(CH2Cl2) / tetrahydrofuran; diethyl ether; pentane / 23 °C 8.1: 84 percent / KOH / methanol; H2O / Heating 9.1: Cl2ZrCp2 / 1,2-dichloro-ethane / 1 h / 23 °C 9.2: 90 percent / Cl2Ni(PPh)2; n-BuLi; PPh3 / tetrahydrofuran / 1 h / 23 °C View Scheme

1.1: 85 percent / PPh3; I2; imidazole / CH2Cl2 2.1: t-BuLi / diethyl ether; pentane / 0.5 h / -78 °C 2.2: ZnBr2 / tetrahydrofuran; diethyl ether; pentane / -78 - 0 °C 2.3: 91 percent / Cl2Pd(dppf)(CH2Cl2) / tetrahydrofuran; diethyl ether; pentane / 2 h / 23 °C 3.1: t-BuLi / diethyl ether; pentane / 0.5 h / -78 °C 3.2: ZnBr2 / tetrahydrofuran; diethyl ether / -78 - 0 °C 3.3: 90 percent / Cl2Pd(dppf)(CH2Cl2) / tetrahydrofuran; diethyl ether; pentane / 23 °C 4.1: t-BuLi / diethyl ether; pentane / 0.5 h / -78 °C 4.2: ZnBr2 / tetrahydrofuran; diethyl ether / -78 - 0 °C 4.3: 79 percent / Cl2Pd(dppf)(CH2Cl2) / tetrahydrofuran; pentane; diethyl ether / 23 °C 5.1: t-BuLi / diethyl ether; pentane / 0.5 h / -78 °C 5.2: ZnBr2 / tetrahydrofuran; diethyl ether / -78 - 0 °C 5.3: 83 percent / Cl2Pd(dppf)(CH2Cl2) / tetrahydrofuran; diethyl ether; pentane / 23 °C 6.1: 81 percent / KOH; H2O / methanol / 2 h / Heating 7.1: Cl2ZrCp2 / 1,2-dichloro-ethane / 8 h / 23 °C 7.2: 88 percent / I2 / tetrahydrofuran; 1,2-dichloro-ethane / 0.25 h / 0 °C 8.1: t-BuLi / diethyl ether; pentane / -78 °C 8.2: ZnBr2 / diethyl ether; tetrahydrofuran / -78 - 0 °C 8.3: Cl2Pd(dppf)(CH2Cl2) / tetrahydrofuran; diethyl ether; pentane / 23 °C 9.1: 84 percent / KOH / methanol; H2O / Heating 10.1: Cl2ZrCp2 / 1,2-dichloro-ethane / 1 h / 23 °C 10.2: 90 percent / Cl2Ni(PPh)2; n-BuLi; PPh3 / tetrahydrofuran / 1 h / 23 °C View Scheme

1.1: Br2 / Fe / CH2Cl2 2.1: 0.83 g / 2,6-pyridinedicarboxylic acid; ammonium cerium(IV) nitrate / H2O; acetonitrile / 20 °C 3.1: 100 percent / CH2Cl2 / 40 h 4.1: NaOMe / toluene / 2 h / 0 - 20 °C 5.1: 96 percent / maleic anhydride / toluene / 4 h / Heating 6.1: LDA; tributyltin hydride / tetrahydrofuran; hexane / 2 h 6.2: Ag2O / BF3*OEt2 / CH2Cl2 / 2 h View Scheme

1.1: MnO2 / diethyl ether; H2O 2.1: Br2 / Fe / CH2Cl2 3.1: 0.83 g / 2,6-pyridinedicarboxylic acid; ammonium cerium(IV) nitrate / H2O; acetonitrile / 20 °C 4.1: 100 percent / CH2Cl2 / 40 h 5.1: NaOMe / toluene / 2 h / 0 - 20 °C 6.1: 96 percent / maleic anhydride / toluene / 4 h / Heating 7.1: LDA; tributyltin hydride / tetrahydrofuran; hexane / 2 h 7.2: Ag2O / BF3*OEt2 / CH2Cl2 / 2 h View Scheme