Using CC(C)(C)OC(=O)OC(C)(C)C, O=C(O)c1c(F)cc(F)c(F)c1F to produce CC(C)(C)OC(=O)c1c(F)cc(F)c(F)c1F, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.