ABSTRACT

Many biologically active compounds are chiral.  One optical isomer shows biologically activity but not the other one.  For example, sodium l-glutamate can be tasted, but not the d-isomer.  Proteins in living organisms are composed of l-amino acids and not of their d-isomers because materials in a living systems are made of optically active isomers.  However, all artificial preparative methods in the absence of a chiral source give racemic compounds.  On the earth, why and how optical isomers were produced selectively or predominantly in the absence of any chiral source, is an important question.

Many chemists have attempted to prepare optically active compounds without using any chiral source.  In most of such efforts, enantioselective photoreaction of achiral amides in its chiral crystal to β–lactams is accomplished.

The photoreaction of amides in the inclusion complex with a chiral host and its chiral crystal gives optically active β–lactams.  In particular, the preparation of optically active β–lactams in the absence of chiral source is of importance because hydrolysis of β–lactams affords β–aminoacids in relation to the origin of optically active compounds on the earth.