Synthesis and biological evaluation of 2,6-dichloropurine bicyclonucleosides containing a triazolyl-carbohydrate moiety.

A series of bicyclic nucleosides containing a triazolyl-carbohydrate moiety were synthesized and their antitumor activity in vitro for human cancer cell lines was also tested. Compound 11 was synthesized efficiently with 3,6-anhydro sugar 7 as raw material, while compound 7 was prepared from 1,2;5,6-di-O-isopropylidene-α-d-glucose. Compounds 12a-e were synthesized by treating compound 11 with alkynes, catalyzed by copper(I). After removal of the acetyl protecting groups, the target compounds 5a-e showed significant inhibitory activity against EC109, PC-3, MGC-803, and HGC-7 cell lines.