ammonium acetate in acetic acid T=140°C; 6 h;

1: tetrahydrofuran / -75 °C 2: cupric chloride, cupric oxide / acetone; H2O 3: 95 percent / ammonium acetate / acetic acid / 6 h / 140 °C View Scheme

trifluoroacetic acid 2 h; Irradiation;