Production method for carbonate compound and methacrylate or ester thereof

The present invention pertains to a production method for a carbonate compound and a methacrylate or an ester thereof, having: a step (a1) in which hexachloroacetone and hydrogen chloride are obtained from acetone and chlorine molecules; a step (a2) in which a dialkyl carbonate and chloroform are obtained from hexachloroacetone and an alkyl alcohol; a step (b1) in which a 1, 1, 1-trichloro-2-methyl-2-propanol is obtained from chloroform and acetone; steps (b2 + b3 or b4) in which methacrylate or an ester thereof and hydrogen chloride are obtained from 1, 1, 1-trichloro-2-methyl-2-propanol and water or alcohol; and a step (c1 or c2) in which hydrogen chloride and oxygen molecules are caused to react and chlorine molecules are obtained.