Stereoselective synthesis of 2'-O-(2-methoxyethyl)ribonucleosides: Neighboring-group participation of the methoxyethoxy group in the ribosylation step

Article abstract of DOI:10.1002/hlca.19960790716

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 stereoselectivity.