Synthesis and hybridization property of an oligonucleotide containing a 3′-thioformcetal linked pentathymidylate

A pentathymidylate fully substituted with 3′-thioformacetal internucleotidic linkages was synthesized and subsequently incorporated into an oligonucleotide (ON) 15mer. Tm analysis was performed on the resulting ON hybridized with its complementary RNA. This duplex demonstrated slightly improved binding affinity relative to the control phosphate diester ON/RNA hybrid.