Using C=CCBr, COC(=O)CC1(C)CCc2c(C)c(O)c(C)c(C)c2O1 to produce C=CCOc1c(C)c(C)c2c(c1C)CCC(C)(CC(=O)OC)O2, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.