manganese(IV) oxide in diethyl ether T=20°C; 12 h;

1: 4-ethynyl-1-methoxy-benzene With n-butyllithium in tetrahydrofuran; hexane T=0°C; 0.25 h; Inert atmosphere; 2: formic acid methyl ester in tetrahydrofuran; hexane T=0 - 20°C; 2.08333 h; Inert atmosphere;

1.1: EtMgBr / tetrahydrofuran; diethyl ether / 1.5 h / 45 °C 1.2: 59 percent / tetrahydrofuran; diethyl ether / 5 h / 0 - 20 °C 2.1: 94 percent / MnO2 / diethyl ether / 12 h / 20 °C View Scheme

1.1: triethylamine; bis-triphenylphosphine-palladium(II) chloride; copper(l) iodide / 0.17 h / 20 °C / |Inert atmosphere 1.2: |Inert atmosphere 2.1: manganese(IV) oxide / dichloromethane / 20 °C 3.1: n-butyllithium / tetrahydrofuran; hexane / 0.25 h / 0 °C / |Inert atmosphere 3.2: |Inert atmosphere 4.1: manganese(IV) oxide / dichloromethane / 20 °C View Scheme

1.1: manganese(IV) oxide / dichloromethane / 20 °C 2.1: n-butyllithium / tetrahydrofuran; hexane / 0.25 h / 0 °C / |Inert atmosphere 2.2: |Inert atmosphere 3.1: manganese(IV) oxide / dichloromethane / 20 °C View Scheme

1.1: n-butyllithium / tetrahydrofuran; hexane / 0.25 h / 0 °C / |Inert atmosphere 1.2: |Inert atmosphere 2.1: manganese(IV) oxide / dichloromethane / 20 °C View Scheme

1,1'-bis-(diphenylphosphino)ferrocene; [RhCl(η2:η2-cycloocta-1,5-diene)]2; chlorobenzene T=90 - 140°C; 24.5 h; Inert atmosphere;