Synthesis of [ 18F]2-deoxy-2-fluoro- d-glucose from highly reactive [ 18F]tetraethylammonium fluoride prepared by hydrolysis of [ 18F]fluorotrimethylsilane

18F-Labeled fluorotrimethylsilane was prepared by nucleophilic substitution of chlorotrimethylsilane with reactor produced [ 18F]fluoride. Hydrolysis of fluorotrimethylsilane by aqueous tetraethylammonium hydroxide followed by removal of water with a mechanical pump gave a powerful source of no carrier added nucleophilic 18F. Reaction of this purified 18F preparation with 4,6-benzylidene-1-β-O-methyl d-mannopyranoside-2.3-cyclic sulfate was complete in 2 min at 80°C and gave two labeled products with similar retention times on reverse phase HPLC. Allowing for decay and handling losses during deprotection, the maximum yield of [ 18F]2-deoxy-2-fluoro- d-glucose from no-carrier added tetraethyl-ammonium fluoride was 50%. Incorporation of 18F into organic products was 30% complete in 10 min at room temperature. An identical time-course was observed for reaction of 3-O-triflyl-1,2-5,6-diisopropylidene- d-allofuranose, the starting material for 3-deoxy-3-fluoro- d-glucose. Reaction of tetraethylammonium fluoride with chlorotrimethylsilane was more rapid and much more tolerant of water than the fluorosugar reactions. Chlorotrimethylsilane can be used to recover unreacted 18F from reaction mixtures.