Bulletin des societes chimiques belges vol:101 issue:2 pages:119-130
1-(2,3-dideoxy-beta-D-erythro-hexopyranosyl)thymine was used at several positions as nucleoside substitute in the synthesis of oligonucleotides using the H-phosphonate chemistry. A 13-mer with one hexose nucleoside substitution at each end had equivalent hybridization properties as compared to the non-modified 13-mer. However, addition of a second analogue at each end or modification in the middle of a 13-mer caused a sharp decrease in melting temperature. Substitution at the 3'-end with two nucleoside analogues was necessary to withstand the action of snake venom phosphodiesterase.