Diastereomeric process control in the synthesis of 2'-O-(2-methoxyethyl) oligoribonucleotide phosphorothioates as
Vasulinga T Ravikumar1, Douglas L Cole
1Isis Pharmaceuticals, Carlsbad, California 92008, USA. vravikumar@isisph.com
Abstract:
Coupling of 2'-O-methoxyethylsubstituted nucleoside phosphoramidites to 5'-hydroxyl group of a nucleoside or nucleotide on solid support is under stereochemical process control and is independent of scale, concentration, synthesizer, ratio of amidite diastereomers, solid support etc. However, activators and phosphate protecting groups do play a role in influencing the ratio of phosphorothioate diesters obtained by sulfurization of phosphite triesters.
Related Concept Videos
RNA Interference
This process occurs naturally in cells, often through the activity of genomically-encoded microRNAs. Researchers can take advantage of this mechanism by introducing synthetic RNAs to deactivate specific genes for research or therapeutic purposes. For example, RNAi could be used...
Alkylation of β-Diester Enolates: Malonic Ester Synthesis
Olefin Metathesis Polymerization: Overview
Ruthenium-based Grubbs catalyst is the most commonly used catalyst for olefin metathesis polymerization. Grubbs catalyst consists of a...
Phosphodiester Linkages
Olefin Metathesis Polymerization: Acyclic Diene Metathesis (ADMET)
Similar to cross-metathesis, ADMET also involves the formation of metallacyclobutane intermediate by [2+2] cycloaddition of one of the double bonds of a terminal diene with...
Oxidation of Alkenes: Syn Dihydroxylation with Osmium Tetraoxide


