FIELD: chemical industry. SUBSTANCE: described is method of purification of beta-anomer-enriched nucleoside. Method comprises (a) preparing mixture containing R'' and beta-anomer-enriched glucoside of formula 1B: 
wherein each X is independently selected from hydroxyprotecting groups, and R' is nucleic base of formula II: 
wherein W is amino protecting group and R'' is nucleic base of formula III, 
wherein W' is aminprotecting group or hydrogen in high-boiling solvent; (b) diluting mixture with organic solvent selected from group consisting of ethers, esters and nitriles; (c) adding diluted reaction mixture into aqueous acid and (d) maintaining acid mixture thus prepared at temperatures from 70 to 100 C till product of formula IB, wherein W is now W', precipitates. EFFECT: simplified process and increased yield of the desired product. 5 cl, 1 ex
