Can circularly polarized light be used to obtain chiral compounds of high optical purity?

Summary

The production of optically active compounds starting from optically inactive material and with the help only of circularly polarized light is briefly discussed. This problem is possibly related to the appearance of optical activity on earth. Some aspects of photochemical asymmetric synthesis of helicenes are given, the optical yields being always lower than 1%. The possibility of obtaining much higher optical purity by using partial asymmetric photodecomposition of a racemic mixture is then discussed. The kinetic treatment allows the prediction that at the end of the destruction the recovered material must be of high optical purity. An experimental demonstration of the correctness of the calculations is shown in the case of dl camphor. Camphor of 20% optical purity could be isolated after prolonged photolysis by circularly polarized light.