Solvent-free, microwave assisted 1,3-cycloaddition of nitrones with vinyl nucleobases for the synthesis of N,O-nucleosides

A number of 4′-aza-2′,3′-dideoxy nucleosides have been synthesized in good yields and short reaction times by straightforward microwave assisted 1,3-cycloaddition of vinyl nucleobases with nitrones, in the absence of solvent. The vinyl nucleobases are used, for the first time, in their unprotected form.