Triose-reductone-C14 was obtained by treating D-glucose-1-C14 with sodium hydroxide in the presence of lead acetate at elevated temperatures. Carbon atoms four, five, and six, as well as carbon atoms one, two, and three, of the D-glucose molecule are shown to contribute to the triose-reductone yield. The formation of triose-reductone was found not to be accompanied by glycerol formation. Mechanisms for fragmentation of reducing sugars are discussed in the light of these findings.