ABSTRACT
Photochemical reactions-asymmetric as well as nonasymmetric ones-take their outset from electronically excited states of the reactant. This chapter discusses photoreactions where the asymmetric induction is introduced by cpl, i.e., in the absorption process. There are several types of systems where the photoenantiomerization proceeds through a defined intermediate in a photoinduced stationary state. Cpl-induced asymmetric photochemistry is a way to conduct absolute asymmetric synthesis. The field is well developed. The method depends on the differential absorption of left and right circularly polarized radiation by the enantiomeric species of the reactants and thus on their g factor. Asymmetric photochemistry is intensively discussed as one of the possibilities for the origin of the observed homochirality of amino acids and saccharides in biological systems. The range of asymmetric photochemistry was extended to shorter wavelengths by the use of synchrotron radiation and two-photon excitation.
