1] Advanced 5′-silyl-2′-orthoester approach to RNA oligonucleotide synthesis

Abstract

Publisher Summary This chapter describes the synthesis of RNA oligonucleotide using 5´-silyl-2´-orthoester approach. For some applications, the RNA is of sufficient purity to use without further processing. After synthesis of an RNA oligonucleotide, the 2´-orthoester protected RNA is water soluble and significantly more stable for degradation than the final fully deprotected RNA product. These features of the 2´- orthoester group enable the RNA to be easily handled in aqueous solutions. The 2´-orthoester groups interrupt secondary structure. This property has made it possible to analyze and purify RNA oligonucleotides of every sequence regardless of secondary structure. This includes 10 to 15 base-long homopolymers of guanosine. Finally, when the RNA is ready for use, the 2´-orthoester groups are completely removed in less than 30 minutes under extremely mild conditions in common aqueous buffers. These unique properties of the 5´-silyl ether and 2´-orthoester protecting groups have made it possible to routinely synthesize high-quality RNA oligonucleotides.