Using O=C([O-])CC1CCC2(CC1)OOC1(O2)C2CC3CC(C2)CC1C3 to produce O=C(O)CC1CCC2(CC1)OOC1(O2)C2CC3CC(C2)CC1C3, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.