| abstract |
FIELD: chemical industry. SUBSTANCE: described is diastereoselective method of preparing optionally active cis-nucleoside and its analogues or derivatives of formula (I): wherein W,R 1 ,R 2 •X are as defined in claim 1. Purine or pyrimidine base or its analogue or derivative is subjected to glycolization with intermediate compound of formula IIa: or IIb: wherein R 3 L are as defined in claim 1 using Lewis acid in formula III: wherein R 5 -R 8 are as defined in claim 1 followed by reducing R 3 glycolized purine or pyrimidine base or its analogue or derivative. EFFECT: simplified process. 32 cl, 3 ex |