Using CON(C)C(=O)CC(NC(=O)OC(C)(C)C)C(=O)OCc1ccccc1 to produce CC(C)(C)OC(=O)NC(CC=O)C(=O)OCc1ccccc1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.