[Oligodeoxyribonucleotides containing 1-(beta-D-3'-deoxy-threo-pentofuranosyl)pyrimidine chains]

Effective methods of multiple incorporations of nucleotides with the inverted configuration of C2' hydroxyl group have been developed. The presence of tU and tC as 3'-terminal oligonucleotide modifications is shown to increase their resistance to snake venom phosphodiesterase. The obtained compounds are promising for the use in antisense biotechnology.