Abstract The reaction of methyl 3, 5-O-isopropylidene-β-d-threo-pentofuranosid-2-ulose (1) with methylmagnesium iodide or methyl-lithium gave methyl 3, 5-O-isopropylidene-2-C- methyl-β-d-lyxofuranoside (3). Compound 1 reacted with diazomethane to give a spiro-
