11C-2-deoxy-D-glucose: synthesis and preliminary comparison with 11C-D-glucose as a tracer for cerebral energy metabolism in PET studies.

11C-2-Deoxy-D-glucose has been prepared by the reaction of 11C-hydrogen cyanide with a stable precursor, 1-deoxy-2,3:4,5-di-O-isopropylidine-1-iodo-D-arabitol, thereby avoiding the synthesis of starting material immediately prior to labeling. Fast, efficient, and reproducible solvent change from dimethyl sulfoxide to ether by flash chromatography enabled the use of diisobutylaluminium hydride in the reduction of the intermediate nitrile. Hydrolysis of the imine-aluminum complex with sulfuric acid, removal of the isopropylidine protecting groups with formic acid, and HPLC purification with an Aminex HPX-87P column yielded 11C-2-deoxy-D-glucose in an aqueous solution, sterile, pyrogen-free, and ready for use in human studies. The radiochemical yield was approximately 20% after a synthesis time of 50 min. The 11C-2-deoxy-D-glucose thus obtained is presently being compared with photosynthetically prepared 11C-D-glucose in PET studies of cerebral metabolism. A preliminary report of the regional cerebral metabolic rate of glucose obtained with the two tracers in a healthy subject with visual stimulation is presented.