Using COC(=O)CCCCCCCCCCCc1c(O)ccc(O)c1CCCCCCCCCCCC(=O)O to produce O=C([O-])CCCCCCCCCCCc1c(O)ccc(O)c1CCCCCCCCCCCC(=O)[O-], please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.