Using CC(C)(C)OC(=O)COC1CCc2c(-c3ccc(C(F)(F)F)cc3)cncc21 to produce O=C(O)COC1CCc2c(-c3ccc(C(F)(F)F)cc3)cncc21, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.