Synthesis and Structural Characterization of 2'-Deoxy-2'-fluoro-l-uridine Nucleic Acids.

Despite the development of artificial l-RNA/DNA as therapeutic molecules, the in-depth investigation on their chemical modifications is still limited. Here, we synthesize a chemically derivatized 2'-deoxy-2'-fluoro-l-uridine building block and incorporate it into oligonucleotides. Our thermo-denaturization and enzymatic digestion experiments reveal their superior stability. Furthermore, one crystal structure of l-type fluoro-DNA is determined to characterize its handedness. Our results reveal the increase of l-helix stability by fluoro-modification and provide the foundation for its future functional application.