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