2′-O-{[2,2-dimethyl-2-(2-nitrophenyl) acetyl] oxy} methyl protecting group for RNA synthesis

A new 2′-OH protecting group, {[2,2-dimethyl-2-(2-nitrophenyl)acetyl]oxy} methyl (DAM), has been successfully applied to RNA oligonucleotides synthesis with high coupling efficiency. The 2′-O-DAM method is fully compatible with reagents and conditions employed in automated solid phase synthesis of RNA. Moreover, it can be easily removed via reduction in near-neutral solution.