Using COC(=O)C1CCC2ON=C(c3ccc(C(C)C)cc3)C2CC1 to produce COC(=O)C1CCc2onc(-c3ccc(C(C)C)cc3)c2CC1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.