Using O=C(OC(=O)C(F)(F)F)C(F)(F)F, Oc1c(F)c(F)cc(F)c1F to produce O=C(Oc1c(F)c(F)cc(F)c1F)C(F)(F)F, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.