A Comparative Study on Phosphate Protecting Groups in Oligonucleotide Synthesis by the Phosphotriester Approach

Abstract

The efficiencies of various of phosphate protecting groups in the synthesis of internucleotidic bonds by the phosphotriester approach have been studied. We found that in the coupling reaction using alkyl groups as phosphate protecting groups of internucleotidic bonds, extensive sulfonation of the 5'-hydroxyl group of nucleoside occurred, whereas when aryl groups were used in place of alkyl groups, the sulfonation did not occur.