title: Two-step regio- and stereoselective syntheses of [19F]- and [18F]-2-deoxy-2-(R)-fluoro-beta-D-allose.
abstract: Replacement of specific hydroxyl groups by fluorine in carbohydrates is an ongoing challenge from chemical, biological, and pharmaceutical points of view. A rapid and efficient two-step, regio- and stereoselective synthesis of 2-deoxy-2-(R)-fluoro-beta-d-allose (2-(R)-fluoro-2-deoxy-beta-d-allose; 2-FDbetaA), a fluorinated analogue of the rare sugar, d-allose, is described. TAG (3,4,6-tri-O-acetyl-1,5-anhydro-2-deoxy-d-arabino-hex-1-enitol or 3,4,6-tri-O-acetyl-d-glucal), was fluorinated in anhydrous HF with dilute F(2) in a Ne/He mixture or with CH(3)COOF at -60 degrees C. The fluorinated intermediate was hydrolyzed in 1N HCl and the hydrolysis product was purified by liquid chromatography and characterized by 1D (1)H, (13)C, and (19)F NMR spectroscopy as well as 2D NMR spectroscopy and mass spectrometry. In addition, (18)F-labeled 2-deoxy-2-(R)-fluoro-beta-d-allose (2-[(18)F]FDbetaA) was synthesized for the first time, with an overall decay-corrected radiochemical yield of 33+/-3% with respect to [(18)F]F(2), the highest radiochemical yield achieved to date for electrophilic fluorination of TAG. The rapid and high radiochemical yield synthesis of 2-[(18)F]FDbetaA has potential as a probe for the bioactivity of d-allose.
authors.affiliation: Department of Nuclear Medicine, Hamilton Health Sciences, 1200 Main Street West, Hamilton, Ontario, Canada L8N 3Z5.
authors.forename: Rezwan
authors.initials: R
authors.lastname: Ashique
authors.forename: Raman V
authors.initials: RV
authors.lastname: Chirakal
authors.forename: Donald W
authors.initials: DW
authors.lastname: Hughes
authors.forename: Gary J
authors.initials: GJ
authors.lastname: Schrobilgen
mesh_terms: D003837:Deoxy Sugars / Q000138:chemical synthesis* / Q000737:chemistry*; D005461:Fluorine; D005462:Fluorine Radioisotopes; D006863:Hydrogen-Ion Concentration; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D015394:Molecular Structure; D013237:Stereoisomerism
chemical_list: C510405:2-deoxy-2-fluoroallose; D003837:Deoxy Sugars; D005462:Fluorine Radioisotopes; D005461:Fluorine