[5′-O-DMTr-2′-OMe-C(Ac)](P-thio-pCyEt)[2′-OMe-U-3′-CE-Phosphoramidite]

[5'-O-(4, 4'-dimethoxytrityl)-2'-O-methyl-C(acetyl)](P-thio-pCyEt)[2'-O-methyl-U-3'-cyanoethyl-Phosphoramidite]