Using CC1(C)Oc2cc3c(c(C(=O)O)c2O1)OC(C)(C)O3, O=C([O-])[O-] to produce COC(=O)c1c2c(cc3c1OC(C)(C)O3)OC(C)(C)O2, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.