STEREOSELECTIVE METHOD OF PREPARING COMPOUNDS, METHODS OF INCREASING YIELD OF TRANS-ISOMERS, AND SALICYLATES OF COMPOUNDS Russian patent published in 2000 - IPC

FIELD: chemical industry, more particularly preparation of optically active analogues of cis nucleosides and derivatives thereof. SUBSTANCE: described is stereoselective method of preparing compounds of general formula I: wherein W is O; X is S; R₁ is hydrogen or acyl, and R₂ is pyrimidine base, or analogue thereof. Method comprises reacting pre sililylated pyrimidine base or analogue thereof with intermediate reactant of general formula IVa; or IVb: wherein R₃ is substituted carbonyl or carbonyl derivative, and G is detachable group. Reaction with pyrimidine base or analogue thereof is carried out without addition of Lewis acid as catalyst, and detachable group is halogen, cyan or R⁹SO₂ group wherein R⁹ is alkyl substituted optionally by one or more halogen group, or optionally substituted phenyl followed by optional reduction of R₃ to R₁OCH₂. Also described are methods of increasing yield of trans-isomers and salicylates of compounds. EFFECT: simplified process. 21 cl, 1 ex