1: in diethyl ether T=-15°C; 16 h; 2: With sulfuric acid in dichloromethane T=-15 - 20°C; 20 h;

aluminium trichloride 1) ether, 5 min, 2) ether, 20 deg C, 26 h; Yield given. Multistep reaction. Yields of byproduct given;