ABSTRACT
The asymmetric synthesis of molecules in the ground state (thermal processes) is increasingly becoming the normal mode of synthesis rather than the exception, and it is now usually possible to prepare compounds with excellent degrees of enantio- or diastereoselectivity using modern synthetic methods [1-10]. It is apparent that the level of interest in asymmetric photochemistry has not driven the available procedures to their ultimate limits, and a great deal of work remains to be carried out in this area if stereocontrol is to become as high as more "conventional" thermal processes. However, it would not be unreasonable to describe asymmetric photochemistry as a relatively young field. Indeed, diastereodifferentiating photochemical reactions induced by chiral auxiliaries were not extensively explored until the mid-1970s. We reviewed the literature up to mid-1991 in "Asymmetric photochemical reactions in solution" [11] and we have chosen to use the same title for this chapter in an attempt to show areas in which developments have taken place. It is from that point in time onward, through mid-1998, that the current work is focused. However, a description of the associated historical background and a large number of pertinent references may be found in our earlier work. The reader may also be interested in several somewhat older reviews 72on this area [12], including the much cited review by Rau, which still has a good deal of importance to the modern photochemist. Although brief commentaries on theory will be made in the introductory comments for each section, the reader should note that the scope of this chapter is not sufficient for an in-depth analysis, and should instead refer to the original articles for more detailed descriptions.
