A novel method for the synthesis of oligoribonucleotides using 1-(2-cyanoethoxy) ethyl (CEE) as a 2′-hydroxy protecting group has been developed. A CEE group was introduced to the 2′-position of N-acyl-3′, 5′-O-silyl-protected ribonucleosides under acidic conditions in good yields. The 2′-O-CEE group was found to be stable in an aqueous or ethanolic ammonia and was quickly removed by treatment with anhydrous ...