Abstract: | A novel approach for the synthesis of 5′-capped 2′-O-methyloligoribonucleotides on a disulfide-tethered solid support is described. The key step of the synthesis is ZnCl2 promoted coupling of m7GDP imidazolide to a fully deprotected oligonucleotide 5′-phosphate on-support. By this methodology m7G5′pppm2′Apm2′Upm2′Ap has been prepared. |