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 that involves the synchronous addition of a stereoselecting moiety (an aryl sulfenyl directing group) and a protected purine or pyrimidine base to 5-(S)-6-(protected oxy)-4-O-4,5-dihydrofuran in the presence of a Lewis base. This one vessel reaction eliminates the need to prepare separately 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 a beta-anomeric nucleoside as necessary.