Using COC(=O)[C@@H]1CCC[C@@H]2SCC[C@H](NC(=O)C(F)(F)F)C(=O)N21, O=C([O-])[O-] to produce COC(=O)[C@@H]1CCC[C@@H]2SCC[C@H](N(C)C(=O)C(F)(F)F)C(=O)N21, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.