in dimethyl sulfoxide T=195°C; 0.75 h;

in acetic acid-water; ethanol; dimethyl sulfoxide

1.1: n-butyllithium / hexane; tetrahydrofuran / 0.75 h / Cooling with ethanol-dry ice 1.2: 2.5 h 1.3: 5 °C 2.1: dimethyl sulfoxide / 0.75 h / 195 °C View Scheme

1.1: potassium iodide; potassium hydroxide / dimethyl sulfoxide / 10 - 20 °C 2.1: n-butyllithium / hexane; tetrahydrofuran / 0.75 h / Cooling with ethanol-dry ice 2.2: 2.5 h 2.3: 5 °C 3.1: dimethyl sulfoxide / 0.75 h / 195 °C View Scheme

1.1: bromine; iodine / dichloromethane; water / 1.58 h / 20 °C 1.2: 0.5 h 2.1: potassium iodide; potassium hydroxide / dimethyl sulfoxide / 10 - 20 °C 3.1: n-butyllithium / hexane; tetrahydrofuran / 0.75 h / Cooling with ethanol-dry ice 3.2: 2.5 h 3.3: 5 °C 4.1: dimethyl sulfoxide / 0.75 h / 195 °C View Scheme