Synthesis and Stereochemical Behavior of Dioxa[6]helicene Derivatives

We constructed a helically chiral dioxa[6]helicene by assembling simple phenol building blocks by a combination of two simple reactions involving oxidative cross‐coupling followed by dehydrative cyclization. X‐ray analysis and density functional calculations (DFT) revealed that the compound dioxa[6]helicene has a helical structure that undergoes helical inversion rapidly at room temperature. We were able to detect the presence of resolvable helical isomers of (−)‐menthyloxycarbonyl derivative of dioxa[6]helicene by recording 1 H NMR spectra below 0 °C. The investigations of photo physical properties by cyclic voltammetry, UV/Vis‐ and fluorescence properties with the aid of time‐dependent DFT calculations were undertaken.