Use of the 1-(2-fluorophenyl)-4-methoxypiperidin-4-yl (Fpmp) and related protecting groups in oligoribonucleotide synthesis: stability of internucleotide linkages to aqueous acid.
The internucleotide linkage of uridylyl-(3'-->5')-uridine (r[UpU]) does not undergo detectable hydrolytic cleavage or migration in ca. 24 hr in 0.01 mol dm-3 hydrochloric acid (pH 2.0) at 25 degrees C. However, unlike r[UpU] and previously examined relatively high molecular weight oligoribonucleotides, oligouridylic acids are very sensitive to aqueous acid under the latter conditions (pH 2.0, 25 degrees C). Thus when the 1-(2-fluorophenyl)-4-methoxypiperidin-4-yl (Fpmp) group is used to protect the 2'-hydroxy functions in the synthesis of r[(Up)9U] and r[(Up)19U], the final unblocking process must be carried out above pH 3 if hydrolytic cleavage and migration are to be avoided. It is demonstrated that the rate of acid-catalyzed hydrolysis of the internucleotide linkages of oligoribonucleotides is sequence dependent. As Fpmp groups may be virtually completely removed from average partially-protected oligoribonucleotides within ca. 24 hr at pH 3 and 25 degrees C, it is concluded that Fpmp is a suitable 2'-protecting group even in the synthesis of particularly acid-sensitive sequences.
Capaldi
D C
DC
Department of Chemistry, King's College London, UK.
Reese
C B
CB
D000143:Acids; D001483:Base Sequence; D002851:Chromatography, High Pressure Liquid; D006863:Hydrogen-Ion Concentration; D008969:Molecular Sequence Data; D015394:Molecular Structure; D009843:Oligoribonucleotides / Q000138:chemical synthesis*; D010880:Piperidines / Q000737:chemistry*; D014867:Water
D000143:Acids; D009843:Oligoribonucleotides; D010880:Piperidines; D014867:Water