hydrogen iodide; acetic anhydride T=140°C;

N,N-diethylaniline T=215°C; 0.5 h;

1: 96 percent / K2CO3 / acetone / 12 h / Heating 2: 63 percent / dimethylformamide / 12 h / 190 °C 3: 90 percent / potassium tert-butoxide / tetrahydrofuran / 24 h / Heating 4: 83 percent / triethylamine / CH2Cl2 / 3 h / 20 °C 5: 72 percent / Grubbs' second generation catalyst / CH2Cl2 / 24 h / Heating View Scheme

1: 63 percent / dimethylformamide / 12 h / 190 °C 2: 90 percent / potassium tert-butoxide / tetrahydrofuran / 24 h / Heating 3: 83 percent / triethylamine / CH2Cl2 / 3 h / 20 °C 4: 72 percent / Grubbs' second generation catalyst / CH2Cl2 / 24 h / Heating View Scheme

1: 90 percent / potassium tert-butoxide / tetrahydrofuran / 24 h / Heating 2: 83 percent / triethylamine / CH2Cl2 / 3 h / 20 °C 3: 72 percent / Grubbs' second generation catalyst / CH2Cl2 / 24 h / Heating View Scheme