Using COC(=O)c1ccc2cc(-c3oc(=O)c(C)c(OC(C)=O)c3C)oc2c1 to produce Cc1c(-c2cc3ccc(C(=O)O)cc3o2)oc(=O)c(C)c1O, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.