Chemical synthesis of octadeoxyribonucleotides containing sequence-specific 3'-deoxy-3'-chlorouridine residues and 2'-5' internucleotide linkages by the phosphite chloridite approach.

3'-Deoxy-3'-chlorouridine has been chemically incorporated into two octanucleotides at various positions using in situ prepared phosphite chloridite intermediates. The behaviour of these modified selfcomplementary DNA fragments containing 2'-5' internucleotide bonds in the neighbourhood of 3'-deoxy-3'-chlororibose in respect to chemical sequencing, polynucleotide kinase and T4 DNA ligase has been studied.