sulfuric acid in Petroleum ether T=5 - 10°C; 0.5 h;

1: 1.) H2SO4, 2.) Mg / 1.) 20 deg C, 3 h, 2.) THF, 75 deg C, 30 min, 3.) THF, reflux, 30 min 2: 94 percent / H2SO4 / petroleum ether / 0.5 h / 5 - 10 °C View Scheme

aluminium trichloride