A simple procedure for the preparation of protected 2'-O-methyl or 2'-O-ethyl ribonucleoside-3'-O-phosphoramidites.
Protected 2'-O-methyl and 2'-O-ethyl ribonucleoside-3'-O-phosphoramidites were prepared via alkylation of the ribonucleosides at an early stage in the synthesis. Utilizing a strategy of minimal protection, the alkylation was performed with unprotected cytidine and adenosine, or with O6-protected guanosine and N3,5'-O-protected uridine using methyl or ethyl iodide and sodium hydride. In subsequent steps, the introduction of standard protective groups for oligonucleotide synthesis and the concomitant separation from 3'-O-alkylated isomers was accomplished. A modification of the phosphitylation procedure permitted facile isolation of the desired phosphoramidites which show high coupling efficiencies in oligomer assembly.
Wagner
E
E
Institute for Molecular Pathology, Vienna, Austria.
Oberhauser
B
B
Holzner
A
A
Brunar
H
H
Issakides
G
G
Schaffner
G
G
Cotten
M
M
Knollmüller
M
M
Noe
C R
CR
D004980:Ethane / Q000737:chemistry; D007455:Iodine; D009682:Magnetic Resonance Spectroscopy; D008697:Methane / Q000737:chemistry; D008745:Methylation; D009841:Oligonucleotides / Q000138:chemical synthesis*; D009943:Organophosphorus Compounds / Q000138:chemical synthesis*; D012263:Ribonucleosides / Q000138:chemical synthesis*
D009841:Oligonucleotides; D009943:Organophosphorus Compounds; D012263:Ribonucleosides; D007455:Iodine; D004980:Ethane; D008697:Methane