sodium acetate; acetic anhydride; potassium carbonate 1.) 70 deg C, 10 h, 2.) EtOH, reflux, 4 h; Yield given. Multistep reaction. Yields of byproduct given;

1: 3-Ethoxycarbonyl-4-(m-methoxyphenyl)-3-butensaeure; acetic anhydride With sodium acetate 3 h; Heating; 2: With sodium hydroxide in ethanol; water T=20°C; 15 h; 3: methanol With sulfuric acid 17 h; Heating;