One vessel stereoselective glycosylation of purines and pyrimidines

摘要

A process for the preparation of 2',3' dideoxynucleosides, 2'-deoxynucleosides, and 2',3'-dideoxy-2',3'-didehydronucleosides is provided that includes the synchronous addition of a stereoselecting moiety (a directing group) and a protected purine or pyrimidine base to 5-(S)-6-(protected-oxy)-4,5-dihydrofuran in the presence of a Lewis acid. This one vessel reaction eliminates the need to separately prepare and purify a 2'-substituted ribose derivative that in a second step is condensed with a purine or pyrimidine base. The process can be easily modified to increase the stereoselectivity of formation of the beta -anomeric nucleoside as necessary.