METHOD OF SYNTHESIS OF NUCLEOSIDE ANALOGS Russian patent published in 2003 - IPC

FIELD: organic chemistry, chemical technology, biochemistry of nucleic acids. SUBSTANCE: invention relates to method of synthesis of 2',3'-O-alkylidene-β-nucleoside analog that involves interaction of 2',3'-O-alkylidene-β-furanosyl halogenide of the formula (1) where R₃ and R₄ mean hydrogen atom or (CH₂)_nQ where n is a whole number from 1 to 6; Q means hydrogen atom or -OR₇; R₅ and R₆ mean (C₁-C₆)-alkyl; R₇ means hydrogen atom or protective group; Y means chlorine or bromine atom with heterocycle of the formula (2) where each of R₈ means hydrogen atom, phenyl, phenyl substituted with halogen atom, OR₇ or NR₇R₇; R₇ means hydrogen atom, phenyl, phenyl substituted with halogen atom or protective group. Reaction is carried out in dimethylsulfoxide medium or in mixture of polar solvents where dimethylsulfoxide volume is at least about 15% in the presence of sodium t-butoxide or potassium t-butoxide as a strong base. Molar ratio of 2',3'-O-alkylidene-β-furanosyl halogenide to heterocycle is in the limit from about 1:1 to about 3:1. Molar ratio of strong base to heterocycle is from about 1:1 to about 8:1. Method provides decrease of ratio of anomers α : β. EFFECT: improved method of synthesis. 17 cl, 1 tbl, 4 ex