1: imidazole / dimethylformamide / 10 h / 55 °C 2: 61 percent / CuBr / chlorobenzene / 4 h / 115 °C 3: 96 percent / aq. NaOH / methanol; tetrahydrofuran 4: 93 percent / Li, NH3 / tetrahydrofuran / 2 h / -78 °C 5: 1.) PDC, 2.) NaClO2, NaH2PO4 / 1.) 5 h, 2.) 2-methyl-2-butene, t-BuOH, 20 min 6: 96 percent / (n-Bu)4NF / tetrahydrofuran / 13 h / 55 °C View Scheme

1: imidazole / dimethylformamide / 10 h / 55 °C 2: 61 percent / CuBr / chlorobenzene / 4 h / 115 °C 3: 96 percent / aq. NaOH / methanol; tetrahydrofuran 4: 93 percent / Li, NH3 / tetrahydrofuran / 2 h / -78 °C 5: 95 percent / (n-Bu)4NF / tetrahydrofuran / 12 h / 55 °C View Scheme

1: imidazole / dimethylformamide / 10 h / 55 °C 2: 61 percent / CuBr / chlorobenzene / 4 h / 115 °C 3: 96 percent / aq. NaOH / methanol; tetrahydrofuran 4: 93 percent / Li, NH3 / tetrahydrofuran / 2 h / -78 °C 5: 1.) n-BuLi, ClPO(NMe2)2, 2.) Li, EtNH2 / 1.) THF, HMPA, 2.) THF, t-BuOH, 0 deg C, 3 h 6: 95 percent / (n-Bu)4NF / tetrahydrofuran / 12 h / 55 °C View Scheme

Multi-step reaction with 2 steps 1: 56 percent / Et2Zn / toluene / 8 h / Ambient temperature2: DIBAL / CH2Cl2  

Multi-step reaction with 3 steps 1: 72 percent / Pb(OAc)4, Cu(OAc)2, pyridine / acetonitrile / 80 °C2: 56 percent / Et2Zn / toluene / 8 h / Ambient temperature3: DIBAL / CH2Cl2