Hexitol Nucleic Acids (HNA): Synthesis and Properties

While improved alkylation procedures have been worked out for the coupling of purine bases to the anhydrohexitol ring using sulphonate activating groups on the anhydrohexitol ring, the Mitsunobu reaction seems to be the method of choice for synthesis of the pyrimidine analogues. In a mixed sequence context, the anhydrohexitol oligonucleotides still display strong and very selective basepairing properties, with a strong preference for RNA as the complement.