Using COS(=O)(=O)OC, COC(=O)C(=CO)c1cccc(C(F)(F)F)c1 to produce COC=C(C(=O)OC)c1cccc(C(F)(F)F)c1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.