Using CC(C)(C)OC(=O)N1C(=O)C(c2ccc(Cl)cc2)CC1(C)C, O to produce CC(C)(CC(C(=O)O)c1ccc(Cl)cc1)NC(=O)OC(C)(C)C, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.