Bicyclo[3.2.1]amide-DNA: Synthesis and base-pairing properties

A new oligonucleotide analog, bicyclo[3.2.1]-amide-DNA was synthesized. A h omo-adenylate sequence of this analog, efficiently forms hetero-duplexes wi th complementary natural DNA and RNA. The corresponding homo-thymidylate se quence, however, does not base-pair to complementary DNA and RNA, but forms a stable duplex with the homo-adenylate oligomer of the same backbone type . The structure of this duplex is virtually enantiomeric to that of a natur al B-DNA, as inferred from CD-spectroscopy.