Some observations relating to the use of 1-aryl-4-alkoxypiperidin-4-yl groups for the protection of the 2′-hydroxy functions in the chemical synthesis of oligoribonucleotides

Abstract

The comparative rates of acid-catalysed removal of ten 1-aryl-4-methoxypiperidin-4-yl 8 (R = Me) [including the previously reported Ctmp 5 and Fpmp 6] protecting groups for the 2′-hydroxy functions in oligoribonucleotide synthesis are discussed. These studies have led to the development of the 1-(4-chlorophenyl)-4-ethoxypiperidin-4-yl (Cpep) protecting group 8 (R = Et, R¹ = R² = H, R³ = Cl) which is both more stable than the Ctmp and Fpmp groups at pH 0.5 and more labile at pH 3.75. The influence of the ribonucleoside aglycone on the stability of the 2′-O-Fpmp and 2′-O-Ctmp protecting groups both at low and high pH is examined.