Uridine oligonucleotide synthesis by the reaction of uridine with tri-(imidazol-1-yl)phosphine

Abstract

Uridine oligonucleotides have been synthesized using tri-(imidazol-1-yl)phosphine. The procedure involves two steps: (i) the reaction of uridine with tri-(imidazol-1-yl)phosphine (< 60 min) and (ii) the in situ oxidation of the resulting phosphite with iodine and water (10 min). Uridine oligonucleotides up to a hexamer were obtained in high yield at a tri-(imidazol-1-yl)phosphine to uridine ratio of 1.5 at –78 °C. The inter-ribonucleotidic linkage of the oligomer consists of 2′–5′– and 3′–5′-linkages, formed in the oxidation process. Additives such as metal cations and polynucleotides in the oxidation process showed a significant effect on the formation of the inter-nucleotidic linkage.