Synthesis of 2'-deoxy-L-nucleosides

摘要

The present invention provides a process for the preparation of a 2'-deoxy-L-nucleoside comprising the following steps:
a) preparing from a suitably protected and activated L-furanose a 2-S-substituted-2-deoxy-L-furanose of the following formula:
wherein B is a heterocyclic or heteroaromatic base, R 8 and R 9 are independently hydrogen or a suitable protecting group; R 7 is a suitable protecting group;
b) cyclizing the 2-S-substituted-2-deoxy-L-furanose to form a cyclonucleoside of the following formula:
and
c) reducing the cyclonucleoside to a 2'-deoxy-L-nucleoside.