Using CCc1c(OCOC)cc(OCOC)c(C(=O)OC)c1CC(=O)OC to produce CCc1c(OCOC)cc(OCOC)c(C(=O)O)c1CC(=O)O, please predict the solvent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.