(3aR,6R,6aR)-6-(benzyloxyMethyl)-2,2-diMethyldihydrofuro[3,4-d][1,3]dioxol-4(3aH)-one

5-O-Benzyl-2,3-O-isopropylidene-D-ribono-1,4-lactone is used as a reagent in the synthesis of erythrose, ribose and substituted pyrrolidine containing thiazolidinedione derivatives which exhibit antihyperglycemic activity. Also a useful synthetic intermediate in the synthesis of Cyclopentenylcytosine (C989800).