L-Ornithine derivatives of thymine, and thymidine gave oligomers by so
lid phase elongation reactions. These oligomers 2 and 3, however, hard
ly interact with the complementary polynucleotide. Conformational stud
ies of the oligomers with CD and NMR revealed that stable intramolecul
ar hydrogen bonding was formed between thymine base and ornithine unit
.