Reaction of l-halogenoses with nitrogen nucleophiles in the presence of tert-amine. Synthesis of 2'-deoxyribofuranosyl and arabinofuranosyl pyrimidines.

Selective introduction of 2'-deoxyribofuranosyl and arabinofuranosyl moieties onto one of two nitrogen atoms in the pyrimidine ring was demonstrated by the reaction of 1-glycosyl chlorides with pyrimidines protected by the (octylthio)carbonyl group in the presence of tert-amine. Replacing pyrimidines by imidazole derivatives such as benzimidazole and theophylline as nucleophiles gave no nucleosides but orthoamide derivatives.

Synthesis of N1- and N3-glycosyl pyrimidines from protected pyrimidines and halo sugars in the presence of tert-amine.

The reaction of N1- and N3-(octylthio)carbonyl pyrimidines with acylglycosyl halides in the presence of tert-amine affords fully protected nucleosides with (N1-C1') and (N3-C1') glycosidic linkages in good yields. The (octylthio)carbonyl and acyl groups are removed stepwise or at once.