Pia N. Jørgensen, Ulrik S. Sørensen, Henrik M. Pfundheller, Carl E. Olsen and Jesper Wengel
Convergent synthesis of β- and α-1-(3-C-allyl-2-deoxy-D-erythro-pentofuranosyl)thymine and their incorporation into β- and α-oligodeoxynucleotides (ODNs) is described. The thermal stabilities of duplexes formed between modified ODNs and complementary single-stranded DNA and RNA have been evaluated. In all cases stable duplexes are formed, but whereas β-ODNs containing β-3′-C-allylthymidine show moderately lowered thermal stability towards both DNA and RNA, α-ODNs containing α-3′-C-allylthymidine show significantly increased thermal stabilities compared with the corresponding β-ODN reference duplexes. Even more stable duplexes towards both DNA and RNA have been obtained using an α-ODN containing one α-1-[3-C-(3-aminopropyl)-2-deoxy-D-erythro-pentofuranosyl]thymine monomer.