Using CCOC(=O)[C@@H]1CCC(=O)N1C(=O)OC(C)(C)C, O=C([O-])O to produce CCOC(=O)[C@H](CCC(C)=O)NC(=O)OC(C)(C)C, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.