Using O, CCOC(=O)c1sc(-c2ccc(OC=C(C)C)c(-n3cnnn3)c2)nc1C to produce CCOC(=O)c1sc(-c2ccc(OCC(C)(C)O)c(-n3cnnn3)c2)nc1C, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.