The 2-cyano-2,2-dimethylethanimine-N-oxymethyl group for the 2'-hydroxyl protection of ribonucleosides in the solid-phase synthesis of RNA sequences.

摘要: The reaction of 2-cyano-2-methyl propanal with 2'-O-aminooxymethylribonucleosides leads to stable and yet reversible 2'-O-(2-cyano-2,2-dimethylethanimine-N-oxymethyl)ribonucleosides. Following N-protection the nucleobases, 5'-dimethoxytritylation 3'-phosphitylation, resulting 2'-protected ribonucleoside phosphoramidite monomers are employed in solid-phase synthesis three chimeric RNA sequences, each differing their ratios purine/pyrimidine. When activation is performed presence 5-benzylthio-1H-tetrazole, coupling efficiencies averaging 99% obtained within 180 s. Upon completion RNA-chain assemblies, removal nucleobase phosphate protecting groups release sequences from solid support carried out under standard basic conditions, whereas cleavage 2'-O-(2-cyano-2,2-dimethylethanimine-N-oxymethyl) protective effected (without releasing alkylating side-products) by treatment tetra-n-butylammonium fluoride (0.5 M) dry DMSO over a period 24-48 h at 55 °C. Characterization fully deprotected polyacrylamide gel electrophoresis (PAGE), enzymatic hydrolysis, matrix-assisted laser desorption/ionization (MALDI) mass spectrometry confirmed identity quality these sequences. Thus, use design new 2'-hydroxyl powerful approach development straightforward, efficient, cost-effective method for chemical high-quality framework interference applications.