Circularly polarized light photodestruction

There has been a sustained interest in the possibility of absolute asymmetric synthesis using physical fields rather than reagents [43]. It has been known for more than a century that circularly polarized light (GPL) can effect the selective transformation (usually photodecomposition/photodestruction) of one enantiomer... 

So we can generate chiral material from racemic or achiral material quite easily. It s just that we couldn t predict ahead of time which one we might get— that is, unless you have an external chiral influence We discussed this general idea when we described the chiral photodestruction of molecules in interstellar space. The chiral force here is the circularly polarized light that is expected to preferentially destroy one enantiomer more rapidly than the other. Chemists know that if you have a saturated solution that is cooling down and ready to crystallize, you can influence which crystal you get from the two racemic possibilities by "seeding" the solution with a chiral seed crystal. This will often initiate the formation of the desired enantiomeric crystal, and then the autocatalysis takes over and more of these enantiomeric crystals are formed. 

Asymmetric photoreactions by circularly polarized light (CPL) are induced through the preferential excitation of one enantiomer. The chiral information is introduced by a physical source of chirality that renders this approach most effective in terms of chiral amplification. Asymmetric photodestruction causes a racemic mixture to be enantiomericaUy enriched when one enantiomer is consumed more rapidly by CPL. Photoderacemization creates an enantiomericaUy enriched reaction mixture when one enantiomer... 

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