A general synthetic method for 2', 3'-unsaturated nucleosides from the corresponding ribonucleosides is described. The 5'-0-silyl protected ribonucleosides were converted to the bisxanthates by reaction with carbon disulfide, followed by alkylation. The bisxanthates on reduction with tri-n-butyltin hydride and deprotection of the 5'-O-silyl group afforded the unsaturated nucleosides. The desulfurization of cyclic thionocarbonates has also been ...
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