Using CCOC(=O)/C=C/C=C(c1ccc(Cl)cc1)c1ccc(Cl)cc1 to produce O=C(O)/C=C/C=C(c1ccc(Cl)cc1)c1ccc(Cl)cc1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.