1-propenyl-4,6-o-benzylidene-β-mannopyrannoside-2,3- cyclic sulfate: A new substrate for the synthesis of [F-18]-2-deoxy-2-fluoroglucose

Recently the authors introduced a synthesis of [F-18]-2-deoxy-2-fluoroglucose based upon the reaction of methyl 4,6-O-benylidene-β-mannopyranoside- 2,3,-cyclic sulfate with [F-18]-fluoride. The reaction works well but the removal of the glycosidic methyl group requires the use of boron tris(trifluoroacetate), an obnoxious reagent, and is occasionally erratic. To remove this difficulty, the authors have synthesized the title compound in which the anomeric hydroxyl group is protected as a vinyl ether. The compound reacts rapidly with fluorine-18 tetramethyl-ammonium fluoride in acetonitrile and the protecting groups are easily removed in 2N HCl to give pure 2-deoxy-2-fluoroglucose in excellent yield