1: 4-ethynyl-1-methoxy-benzene With lithium diisopropyl amide in tetrahydrofuran T=-78 - 20°C; Inert atmosphere; 2: N-methoxy-N-methyl-3-phenylpropiolamide in tetrahydrofuran T=-78 - 20°C; Inert atmosphere;

aluminium trichloride in dichloromethane T=-78°C; 1 h; Yield given;

1.1: 4-(N,N-dimethlyamino)pyridine; dicyclohexyl-carbodiimide; triethylamine / dichloromethane / 0 - 20 °C / |Inert atmosphere 2.1: lithium diisopropyl amide / tetrahydrofuran / -78 - 20 °C / |Inert atmosphere 2.2: -78 - 20 °C / |Inert atmosphere View Scheme

1: 0.24 N aq. NaOH / ethanol / 1.5 h 2: thionyl chloride / 16 h 3: AlCl3 / CH2Cl2 / 1 h / -78 °C View Scheme

1: 1.) AlCl3, 3.) NaHCO3 2: 1 N aq. HCl / CH2Cl2 3: 0.24 N aq. NaOH / ethanol / 1.5 h 4: thionyl chloride / 16 h 5: AlCl3 / CH2Cl2 / 1 h / -78 °C View Scheme

1: thionyl chloride / 16 h 2: AlCl3 / CH2Cl2 / 1 h / -78 °C View Scheme

1: 51.5 percent / pyridinium chlorochromate / CH2Cl2 / 1.5 h / Ambient temperature 2: 1.) n-butyllithium / 1.) THF, hexane, -78 deg C, 15 min, 2.) THF, hexane, RT 3: 80 percent / 10percent chromic acid / acetone / 0.5 h / Ambient temperature View Scheme

1: 1.) n-butyllithium / 1.) THF, hexane, -78 deg C, 15 min, 2.) THF, hexane, RT 2: 80 percent / 10percent chromic acid / acetone / 0.5 h / Ambient temperature 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