PREPARATION OF GLUCOFURANOSE DERIVATIVE OXIDE

PURPOSE:To obtain the titled compound useful as an intermediate for synthesizing X-ray contrast medium, etc. industrially advantageously using inexpansive raw materials without causing bad smell, waste, etc., by oxidizing a specific glucofuranose derivative with a ruthenium compound and a hypochlorite. CONSTITUTION:A glucofuranose derivative (e.g., 1,2:5,6-di-O-isopropylidene-alpha- D-glucofuranose, etc.) shown by the formula I (R1 and R2 are 1-4C lower alkyl) is oxidized with a ruthenium compound (e.g., ruthenium dioxide, etc.) and a hypochlorite (e.g., sodium hypochlorite, etc.), the reaction solution is extracted with chloroform, etc., the chloroform layer is dried, concentrated, crystallized, to give the desired compound shown by the formula II or formula III. This compound is reduced, iodized, and hydrolyzed, to give 3-deoxy-iodo-D-glucose shown by the formula IV for preparing X-ray contrast medium.