RNA Synthesis Using the CEM Group
We have developed a solid-phase synthesis of RNA oligomers with 2-cyanoethoxymethyl (CEM) as the 2′-hydroxyl protecting group. The method allows the synthesis of RNA oligomers with high efficiency and high purity. In this section, we describe the synthesis of CEM amidites and RNA synthesis by using CEM amidites. The advantages of the CEM group include its low steric hindrance, leading to a high coupling yield, and its ease of removal under mild conditions without any decomposition of the RNA oligomers.
Keywords2-cyanoethoxymethyl CEM TBAF 2′-hydroxyl protecting group RNA Solid-phase synthesis Phosphoramidite SiRNA
The research described here was supported in part by grants from the New Energy and Industrial Technology Development Organization (NEDO) of Japan for its Functional RNA Project. We thank Dr. G. E. Smyth, Discovery Research Laboratories in Tsukuba, Nippon Shinyaku Co., for helpful discussions and suggestions concerning the manuscript.
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