2' c methyluridine 2 2' c methyluridine phosphoramidite 2 2′-C-alkylnucleotides 2 3',5' di o acetyl 2' c methyluridine 2 3',5' di o acetyl 2' o tetrahydropyranyl 2' c methyluridine 2 3',5' o (tetraisopropyldisiloxane 1,3 diyl) 2' c methyluridine 2 5' o dimethoxytrityl 2' c methyluridine 3 o (2 cyanoethyl n,n diisopropyl phosphoramidite) 2 RNA analogues 2 RNA derivative 2 Sugar conformation 2 article 2 chemical modification 2 chemical reaction 2 chemical structure 2 hydroxyl group 2 oligonucleotide 2 phosphoramidic acid derivative 2 priority journal 2 reaction analysis 2 stereochemistry 2 synthesis 2 unclassified drug 2 uridine derivative 2