The circular dichroism spectra of the N-2, 4-dinitrophenyl (Dnp)-derivatives of some aliphatic olefinic and acetylenic α-amino acids were examined in order to compare them with those of N-Dnp-α-amino acids with alkyl and aryl side chains. All of the L-series compounds showed negative Cotton effects of moderate strength near 400 nm. The results were explained by application of exciton chirality theory to the probable conformers. Such an explanation can also be extended to S-containing and aromatic amino acids. Thus, the results should be useful for assigning the absolute configurations of new amino acids and related amines.
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