Synthesis of oligodeoxyribonucleotides containing hydroxymethylphosphonate bonds in the phosphoramidite method and their hybridization properties

A set of diastereomeric TpT phosphoramidite building blocks, 1-f and 1-s, containing an alkaline-labile hydroxymethylphosphonate (HMP) linkage were synthesized. Dodecadeoxynucleotides incorporating the HMP bond were also synthesized by use of each stereochemically pure dimer block under mild conditions in the N-unprotected phosphoramidite method. Moreover, it turned out that HMP-oligonucleotides derived from a fast-eluted dimer block exhibit higher affinity for DNA single and double strands than those containing a slow-eluted one.