Chemical synthesis of RNA via 2′-O-cyanoethylated intermediates

It was found that 2′-O-cyanoethyl group could be removed from 2′-O-cyanoethylated ribonucleoside derivatives by treatment with Bu4NF. This finding was successfully applied to the synthesis of oligoribonucleotides via their 2′-O-cyanoethylated derivatives as key intermediates where a cyanoethyl group was used as the 2′-hydroxyl protecting group. The rate of condensation using this protecting group in the presence of various activators was generally faster than that observed when a TBDMS group was used as the protecting group.