A practical synthesis of (−)fosfomycin from its enantiomer

(+)-cis-(1S, 2R)-Epoxypropylphosphonic acid, the enantiomer of fosfomycin, which is the industrial side-product in the preparation of the antibiotic fosfomycin, was converted into (−)fosfomycin by a seven-step procedure. The esterification of the dihydroxyphosphonic intermediate was the key step. The title compound was obtained in good yield and its optical purity was up to the medicine quality standard of Chinese Pharmacopoeia.