Process for the deoxygenation of nucleosides

摘要

An efficient process for the deoxygenation of 2'- and or 3'-hydroxyl groups of a nucleoside that includes reacting the hydroxyl group with 3-halopropionitrile or 2-nitroethylhalide and carbon disulfide in base to form a 2'- or 3'-(cyanoethylthio or nitroethylthio)thiocarbonyl, that is reductively eliminated and replaced with hydrogen. The deoxygenation process can be used in a wide variety of nucleoside syntheses that require the elimination of the 2'- or 3'-hydroxyl groups, including the preparation of 3'-substituted-2',3'-dideoxynucleosides such as 3'-azido-3'-deoxythymidine and 3'-azido-2',3'-dideoxyuridine.