Optically pure 5,6-dimethylidenebicyclo[2.2.1]hept-2-yl derivatives have been prepared. The sign of the Cotton effects associated with lowest-energy transition of 2–(dicyanomethylidene)-((−)-(1S,4S)-15), (E)-2-(methoxyimino)-((+)-(1S,4S)-16), (Z)-2-(methoxyimino)-5,6-dimethylidenebicyclo[2.2.1]heptane ((−)(1S,4S)-17), and 2,3,5-trimethylidenebicyclo[2.2.1]heptane ((−)-(1R,4S)-18) is opposite to the