Using COC(=O)c1cc(Cl)cc2c1O[C@@H]1CCCC[C@H]21 to produce O=C(O)c1cc(Cl)cc2c1O[C@@H]1CCCC[C@H]21, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.