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: 82 percent / 1.) EtMgBr / tetrahydrofuran / 2 h / 40 °C 2: 73 percent / <CoCp2> / 1 h / 145 °C View Scheme

[Co(η5-C5H5)2] T=145°C; 1 h;

η5-cyclopentadienyl dicarbonyl cobalt in m-xylene 36 h; HeatingIrradiation;