C-Nucleosides Derived from Simple Aromatic Hydrocarbons.

We describe the synthesis, structure and DNA incorporation of a class of novel aromatic C-deoxynucleosides in which benzenes and larger polycyclic aromatics serve as DNA base analogs. Novel approaches have been developed for glycosidic bond formation and for epimenzation of the anomeric substitutents to β-configuration, and we describe some of the properties of such compounds in DNA.

Naphthalene, Phenanthrene, and Pyrene as DNA Base Analogues: Synthesis, Structure, and Fluorescence in DNA.

We describe the synthesis, structures, and DNA incorporation of deoxyribonucleosides carrying polycyclic aromatic hydrocarbons as the DNA "base" analogue. The new polycyclic compounds are 1-naphthyl, 2-naphthyl, 9-phenanthrenyl, and 1-pyrenyl deoxynucleosides. The compounds are synthesized using a recently developed C-glycosidic bond formation method involving organocadmium derivatives of the aromatic compounds coupling with a 1α-chlorodeoxyribose precursor.

Very High Affinity DNA Recognition by Bicyclic and Cross-Linked Oligonucleotides.

We report the synthesis and DNA incorporation of a novel C-5 thiopropyne-substituted thymidine derivative which can be used to bring about covalent crosslinks between two noncomplementary DNA strands. This modified thymine pairs normally with adenine in duplex DNA and is shown not to be destabilizing to DNA double helices. Placement of the thiol-nucleotide near the center of opposing pyrimidine strands in pyr·pur·pyr triple helices results in crosslinking of the pyrimidine strands under aerobic conditions.