Stereoselektive Synthese von 2′-O-(2-Methoxyethyl)ribonucleosiden: Nachbargruppenbeteiligung der Methoxyethoxy-Gruppe bei der Ribosylierung von Heterocyclen

Stereoselective Synthesis of 2′-O-(2-Methoxythyl)ribonucleosides: Neighboring-Group Participation of the Methoxythoxy Group in the Ribosylation Step A new access to 2′-O-(2-methoxyethyl)ribonucleosides, building blocks for second-generation antisense oligonucleotides, is presented. The influence of various reaction parameters on the coupling reaction of 2-O-(2-methoxyethyl)-D -ribose derivatives with heteroaromatic bases as the key step was investigated, and reaction conditions were optimized with regard to formation of the desired β-D -anomers. With Sn²⁺ salts as promotors in polar solvents, these β-D -anomers were formed with a high degree of steroselectivity.