Using CC(=O)O[C@H]1[C@H](C)OC=C[C@@H]1OC(C)=O, O to produce CC(=O)O[C@H]1[C@H](C)OC(O)C[C@@H]1OC(C)=O, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.