Synthesis and conformation of a novel bridged nucleic acid having a trans-fused 3,5,8-trioxabicyclo[5.3.0]decane structure

A novel bridged nucleic acid analogue, 2′-deoxy-trans-3′,4′-BNA thymine monomer, was successfully synthesized. An ab initio calculation and X-ray structure analysis revealed that the trans-fused bicyclo[5.3.0]decane structure of the 2′-deoxy-trans-3′,4′-BNA effectively constrained the sugar puckering in C2′-endo with appropriate γ, δ and χ angles.