1: N,N-dimethyl-formamide / 36 h / 50 °C 2: triethylamine / dichloromethane / 3 h / Inert atmosphere 3: toluene-4-sulfonic acid / tetrahydrofuran; water / 20 °C 4: Grubb's 2nd generation catalyst / dichloromethane / 6 h / 50 °C / Inert atmosphere 5: palladium 10 on activated carbon; hydrogen / ethyl acetate / 2 h 6: 1H-imidazole; iodine; triphenylphosphine / diethyl ether; acetonitrile / 0 °C / Inert atmosphere 7: potassium tert-butylate / tetrahydrofuran / 0 - 20 °C / Inert atmosphere View Scheme

1.1: N,N-dimethyl-formamide / 36 h / 50 °C 2.1: triethylamine / dichloromethane / 3 h / Inert atmosphere 3.1: toluene-4-sulfonic acid / tetrahydrofuran; water / 20 °C 4.1: Grubb's 2nd generation catalyst / dichloromethane / 6 h / 50 °C / Inert atmosphere 5.1: 1H-imidazole; iodine; triphenylphosphine / diethyl ether; acetonitrile / 0 °C / Inert atmosphere 6.1: zinc / dichloromethane / 0 - 20 °C / Inert atmosphere 6.2: 0 - 20 °C / Inert atmosphere 7.1: palladium 10 on activated carbon; hydrogen / ethyl acetate / 2 h 8.1: hydrogenchloride / tetrahydrofuran; water / 20 °C 8.3: 0.17 h View Scheme

1.1: N,N-dimethyl-formamide / 36 h / 50 °C 2.1: triethylamine / dichloromethane / 3 h / Inert atmosphere 3.1: toluene-4-sulfonic acid / tetrahydrofuran; water / 20 °C 4.1: Grubb's 2nd generation catalyst / dichloromethane / 6 h / 50 °C / Inert atmosphere 5.1: 1H-imidazole; iodine; triphenylphosphine / diethyl ether; acetonitrile / 0 °C / Inert atmosphere 6.1: zinc / dichloromethane / 0 - 20 °C / Inert atmosphere 6.2: 0 - 20 °C / Inert atmosphere 7.1: palladium 10 on activated carbon; hydrogen / ethyl acetate / 2 h 8.1: hydrogenchloride / tetrahydrofuran; water / 20 °C 8.3: 0.17 h View Scheme