The bicyclic thymine monomer of alpha-LNA (alpha T-L) was efficiently synth
esised and used in the synthesis of alpha-LNA sequences: incorporation of s
ingle alpha T-L-monomers in alpha-configured oligothymidylates destabilises
the affinity towards both complementary DNA and RNA, whereas a fully modif
ied alpha-LNA sequence displays a very efficient recognition of complementa
ry RNA.