The stereoselective reduction of symmetrical prochiral dicarbonyl compounds bearing enantiotopic carbonyl groups yields several stereogenic centers in one step. In a proof-of-concept study, a new approach is described for the enzymatic desymmetrization of 5-nitrononane-2,8-dione via sequential biocatalytic reduction steps utilizing ketoreductases to yield all possible diastereomers of 5-nitrononane-2,8-diol.