Preparative separations of oligonucleotides containing ara-cytidine by continuous electrophoresis

During the synthesis of a series of dinucleoside phosphates, nucleotides, and simple esters of these nucleotides (1), product separations were carried out by ion-exchange chromatography on Dowex 1X2 when 2′ → 5′ and 3′ → 5′ isomers had to be resolved.Since column chromatography was time consuming and could lead to rearrangements and degradation (2), a new method for isolating the products of a reaction was investigated, viz., the “carrier-free” continuous-flow electrophoresis systems of Barrolier, Watzke, and Gibian (3) and Hannig (4).