A new synthetic approach to the clinically useful, anti-HIV-active nucleoside, 9-(2,3-dideoxy-2-fluoro-β-D-threo-pentofuranosyl)adenine (β- FddA). Introduction of a 2'-β-fluoro substituent via inversion of a readily obtainable 2'-α-fluoro isomer

Article abstract of DOI:10.1016/S0040-4039(98)00014-8

A convenient route to the anti-HIV active compound, 9-(2,3-dideoxy-2- fluoro-β-D-threo-pentofuranosyl)adenine (1, β-FddA) started with the facile introduction of fluorine at C2' from the α-side of protected 9-(β-D- arabinofuranosyl)adenine (ara-A). Inversion of the stereochemistry at C2' was accomplished via a stable vinyl intermediate (6), which underwent stereoselective reduction of the double bond to give the desired 2'-F-threo isomer with the opposite β-fluoro stereochemistry.