Preparation and properties of 2′,5′-linked oligonucleotide analogues containing 3′-O,4′-C-methyleneribonucleosides

Bicyclic nucleoside analogues, 3′-O,4′-C-methyleneuridine and -5-methyluridine, were successfully incorporated into oligonucleotides via connection with 2′,5′-phosphodiester linkage, and hybridization behavior and nuclease stability of the modified oligonucleotides were investigated.