1.1: BuLi / diethyl ether 1.2: 60 percent / diethyl ether 2.1: 81 percent / [cpCo(cod)] / hexane; acetonitrile / 20 h / Heating; irradiadion 3.1: 75 percent / propan-2-ol / 12 h / 70 °C 4.1: KH; t-BuOOH / dimethylformamide; various solvent(s) / 0.5 h / 5 °C View Scheme

tert.-butylhydroperoxide; potassium hydride in N,N-dimethyl-formamide T=5°C; 0.5 h;

1: 81 percent / [cpCo(cod)] / hexane; acetonitrile / 20 h / Heating; irradiadion 2: 75 percent / propan-2-ol / 12 h / 70 °C 3: KH; t-BuOOH / dimethylformamide; various solvent(s) / 0.5 h / 5 °C View Scheme

1: 1.) Mg, EtBr / 1.) THF, 55 degC, 1 h; 2.) THF, romtemp., 1 h 2: 84 percent / H2SO4 / benzene / 20 h / Heating 3: 79 percent / <CoCp(CO)2> / 2 h / 145 °C 4: CsF / ethanol / 87 h / Ambient temperature 5: 65 percent / KOH / ethanol; H2O / 5 h / Ambient temperature 6: 68 percent / Et3N, diphenoxyphosphorylazid / 24 h / Heating 7: 81 percent / 37percent HCl / ethanol; H2O / 2 h / Heating 8: 72 percent / NaNO2 / aq. HCl; H2O / 1 h / 90 - 95 °C View Scheme

1: 84 percent / H2SO4 / benzene / 20 h / Heating 2: 79 percent / <CoCp(CO)2> / 2 h / 145 °C 3: CsF / ethanol / 87 h / Ambient temperature 4: 65 percent / KOH / ethanol; H2O / 5 h / Ambient temperature 5: 68 percent / Et3N, diphenoxyphosphorylazid / 24 h / Heating 6: 81 percent / 37percent HCl / ethanol; H2O / 2 h / Heating 7: 72 percent / NaNO2 / aq. HCl; H2O / 1 h / 90 - 95 °C View Scheme

sulfuric acid

1: 75 percent / propan-2-ol / 12 h / 70 °C 2: KH; t-BuOOH / dimethylformamide; various solvent(s) / 0.5 h / 5 °C View Scheme

1: 73 percent / <CoCp2> / 1 h / 145 °C 2: 73 percent / diethyl ether / 6 h / Ambient temperature 3: 69 percent / m-chlorperbenzoesaeure / CH2Cl2 / 4 h / Ambient temperature 4: 1.) Ac2O; 2.) 2N HCl / 1.) Et3N, reflux, 2 h; 2.) water, reflux, 75 min View Scheme

1: 73 percent / diethyl ether / 6 h / Ambient temperature 2: 69 percent / m-chlorperbenzoesaeure / CH2Cl2 / 4 h / Ambient temperature 3: 1.) Ac2O; 2.) 2N HCl / 1.) Et3N, reflux, 2 h; 2.) water, reflux, 75 min View Scheme

1: 79 percent / <CoCp(CO)2> / 2 h / 145 °C 2: CsF / ethanol / 87 h / Ambient temperature 3: 65 percent / KOH / ethanol; H2O / 5 h / Ambient temperature 4: 68 percent / Et3N, diphenoxyphosphorylazid / 24 h / Heating 5: 81 percent / 37percent HCl / ethanol; H2O / 2 h / Heating 6: 72 percent / NaNO2 / aq. HCl; H2O / 1 h / 90 - 95 °C View Scheme