Using CCOC(=O)C(CC(=O)OC(C)(C)C)C(=O)NOC(C)(C)C to produce CC(C)(C)ONC(=O)C(CC(=O)OC(C)(C)C)C(=O)O, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.