Using COc1c(C)c(C)c(OC)c(C(O)[C@H]2O[C@]2(C)CCC[C@H](C)CCC[C@H](C)CCCC(C)C)c1C to produce COc1c(C)c(C)c(OC)c(C(O)C[C@](C)(O)CCC[C@H](C)CCC[C@H](C)CCCC(C)C)c1C, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.