Using CCOC(C)=O, CONC1(OC(C)=O)CC2(CCC2)Oc2c(C)c(C)cc(C)c21 to produce CONC1CC2(CCC2)Oc2c(C)c(C)c(O)c(C)c21, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.