Using O, CC1(C)OCC(C(=O)Nc2c(I)c(CCC(=O)[O-])c(I)c(NC(=O)C3COC(C)(C)O3)c2I)O1 to produce O=C(Nc1c(I)c(CO)c(I)c(NC(=O)C(O)CO)c1I)C(O)CO, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.