A series of axially chiral bicyclo[3.3.0]octan-3-ones substituted with exocyclic alkenes was prepared and investigated for suitability as a chiroptical trigger for a liquid-crystal-based optical switch. Irradiation of the optically active ketone leads to its efficient photoracemization. Irradiation with circularly polarized light leads to partial photoresolution. The optical and photochemical properties of these ketones were studied and their twisting power for a nematic liquid crystal was measured.