Synthesis and Structure of an α,β‐D‐CNA Featuring a Noncanonical α/β Torsion Angle Combination within a Tetranucleotide

Synthesis and structural analysis of a ( S C5′ , R P )‐configured α,β‐D‐CNA TT within a tetranucleotide composed of four thymidine units showed that the solution structure determined at the dinucleotide level for the α,β‐D‐CNA with α and β torsional angles constrained to noncanonical values [ gauche (+), trans ] was unchanged and imposed a sharp turn in the single‐stranded tetranucleotide. The overall structure of the tetranucleotide T 4 has a hairpin loop shape. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)