1: carbonic acid dimethyl ester With sodium hydride in toluene 1 h; Heating / reflux; 2: 6-chloro-3,4-dihydro-2(1H)-naphthalenone in toluene 24 h; Heating / reflux; 3: With acetic acid in toluene T=0°C;

sodium hydride 0.75 h; Heating;