Using O=[Cr](=O)([O-])Cl, COC(=O)CCCCCC(c1ccc(F)cc1)c1c2c(c(C)c(C)c1OC)CCCC2 to produce COC(=O)CCCCCC(c1ccc(F)cc1)c1c2c(c(C)c(C)c1OC)C(=O)CCC2, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.