3-O-Benzyl-1,2-O-isopropylidene-α-D-glucofuranose-5,6-O-sulfate (1) was treated with sodium salt of dimethyl malonate to obtain, after hydrolysis, methyl 5-(3-O-benzyl-1,2-O-isopropylidene-α-D-erythrofuranos-4-yl)-2- oxotetrahydrofuran-3-carboxylate (3) which was converted to the mixture of methyl (2S,3R,4R)-(7) and (2R,3R,4R)-2-(acetyloxy)-3-(benzyloxy)-4-(formyloxy)-7-oxo-6-oxabicyclo[3.2.1] octane-1-carboxylate (8). The compound 7 was reduced with lithium aluminium hydride to give (1R,2R,3R,4S)-3-(benzyloxy)-5,5-bis(hydroxymethyl)cyclohexane-1,2,4-triol (9) which was transformed to (1R,25,4R)-5,5-bis(hydroxymethyl)cyclohexane-1,2,4-triol (14). Treatment of sodium salt of diethyl malonate with 3-O-benzyl-5,6-dideoxy-6-iodo-1,2-O-isopropylidene-α-D-xylo-hexofuranose (19) gave diethyl (3-O-benzyl-5,6-dideoxy-1,2-O-isopropylidene-α-D-xylo-hexofuranos-6-yl) malonate (20) which was converted to (1R,3R)-4,4-bis(hydroxymethyl)cyclohexane-1,3-diol (28) by a similar procedure to that used for 14.