The invention is 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:
1
wherein R is selected from the group consisting of C
1-6
alkyl and C
6
-
15
aryl and Bz is benzoyl. The process comprises hydrolyzing said mixture with an enzyme selected from the group consisting of Protease N, Alcalase, Savinase, ChiroCLEC-BL, PS-30, and ChiroCLEC-PC to stereoselectively hydrolyze predominantly one anomer to form a product wherein R
1
is replaced with H. The process also includes the step of separating the product from unhydrolyzed starting material. Additionally, the functional group at the C4 position is stereoselectively replaced with a purinyl or pyrimidinyl or derivative thereof.
该发明是一种从由以下A或B式表示的β和α异构体的异构体混合物中立体选择性地生产
二氧六环核苷类似物的过程:其中R选自由C1-6烷基和C6-15芳基组成的群,Bz为苯甲酰基。该过程包括使用从Protease N、Alcalase、Savinase、ChiroCL
EC-BL、PS-30和ChiroCL
EC-PC组成的酶中选择的酶
水解该混合物,以立体选择性地
水解优选的一个异构体,形成其中R1被H取代的产物。该过程还包括将产物与未
水解的起始材料分离的步骤。此外,C4位置的官能团体立体选择性地被
嘌呤基或
嘧啶基或其衍
生物取代。