Methods for producing nucleoside derivatives and intermediates therefor

Abstract

Novel intermediates of nucleoside derivatives, of which the 6-position of the nucleic acid base moiety is substituted with a halogen atom, are produced. Using those novel intermediates, even substrates, of which the 3'-position of the saccharide moiety is deoxylated, can be substituted at the 2'-position at an extremely high yield. Specifically, by subjecting a 3'-deoxy derivative of inosine to 6-halogenation to give a 6-halide of the derivative, and then subjecting it to 2'-deoxylation/substitution with a fluorine atom or the like, followed by further subjecting it to substitution with an amino group, a hydroxyl group or any other intended substituent at the 6-positioned halogen atom, nucleoside derivatives are produced at a high yield. Methods for producing nucleoside derivatives including 9-(2,3-dideoxy-2-fluoro-.beta.-D-threo-pentofuranosyl)adenine (FddA) and their related compounds, in a simplified manner, at a high yield and at low costs, and especially Economical methods for substituting substrates, of which the 3'-position of the saccharide moiety is deoxylated, at the 2'-position to produce those nucleoside derivatives on an industrial scale are also provided.