Patent ID: 6541625
Filing Date: 2003-04-01
Classification: C07D

Abstract:
A process for stereoselectively producing a dioxolane nucleoside analogue from an anomeric mixture of &bgr; and &agr; anomers represented by the following formula A or formula B: wherein R1 is selected from the group consisting of C1-6 alkyl and C6-15 aryl, and Bz is benzoyl, the process comprising:stereoselectively hydrolyzing said mixture with an enzyme selected from the group consisting of Protease N (Bacillus subtilus protease), AlcalaseÂ® (Subtilisin Carlsberg protease), SavinaseÂ® (Bacillus lentus subtilisin protease), ChiroCLEC-BL (Bacillus licheniformis Subtilisin protease), PS-30 (Pseudomonas cepacia lipase), and ChiroCLEC-PC (Pseudomonas cepacia lipase) to stereoselectively hydrolyze predominantly one anomer to form a product wherein R1 is replaced with H; separating the product from unhydrolyzed starting material to produce a second mixture; stereoselectively replacing the functional group at the C4 position with a purinyl or pyrimidinyl or derivative thereof by reacting said second mixture with a purine or pyrimidine base or derivative thereof.