Synthesis and adduction of fully deprotected oligodeoxynucleotides containing 6-chloropurine

Fully deprotected oligodeoxynucleotides containing 6-chloropurine have been synthesized and used in solution phase reactions with amine nucleophiles to prepare oligonucleotides containing substituted adenine residues. This strategy was used for the preparation of a double-stranded oligonucleotide crosslinked by a 4-carbon tether between N 6 positions of deoxyadenosines in the two strands.