The 2-(4-tolylsulfonyl) ethoxymethyl (TEM) as a new 2′-OH protecting group is reported for solid-supported RNA synthesis using phosphoramidite chemistry. The usefulness of the 2′- O-TEM group is exemplified by the synthesis of 12 different oligo-RNAs of various sizes (14– 38 nucleotides long). The stepwise coupling yield varied from 97–99% with an optimized coupling time of 120 s. The synthesis of all four pure phosphoramidite building blocks is ...