Using CCOC(=O)C1(C(=O)OCC)CC(=C(NC=O)C(=O)OC)C1 to produce CCOC(=O)C1(C(=O)OCC)CC(C(NC=O)C(=O)OC)C1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.