To confirm the in-silico results, a single enantiomer of 1-Mes was isolated using enantioselective HPLC. This single enantiomer was kept in solution at 20 °C and monitored periodically by enantioselective HPLC. This confirmed a slower racemization, for example a ca. 70:30 e.r. mixture was observed after 310 h and a racemate only formed after ca. one month. This is slower by approximately an order of magnitude than the rate of racemization for the [5]helicene C (which fully racemises within several days). Scheme 9: Calculated strain energy in 1-H and 6-H.