(3R-?cis)?-Dihydro-?3-?hydroxy-?4-?(phenylmethoxy)?-2(3H)?-?furanone is a by-product intermediate during the synthesis of 4-Phospho D-Erythronate (P355000), which is an intermediate in the synthesis of pyridoxal 5'-phosphate in some bacteria and an inhibitor of ribose 5-phosphate isomerase. Phosphorylated aldonic acids are strong inhibitors of 6-phosphogluconate dehydrogenase, and 4-phospho-D-erythronate (4PE) and 4-phospho-D-erythronohydroxamate are two of the strongest inhibitors of the Trypanosoma brucei enzyme.