TLC in a search for structural limitations of spontaneous oscillatory in-vitro chiral conversion. α-hydroxybutyric and mandelic acids

Abstract

As a result of our earlier studies, we were the first research group to report the spontaneous oscillatory in-vitro chiral conversion of a considerable number of α-substituted propionic acids (i.e., selected profens, amino acids, and L -lactic acid). It is noteworthy that TLC proved highly instrumental in collecting relevant confirmatory evidence on this issue. Besides, in two papers we introduced a theoretical model and with its aid, we could simulate basic physical and physicochemical features of the discussed process. Reflecting on the oscillatory chiral conversion, we realized that it seems to be a rather general phenomenon and we started contemplating its scope and limitations. It became our primary concern to check whether it is confined to α-substituted propionic acids only or can occur with other classes of chiral compounds also. To this effect, in this study we present empirical (thin-layer chromatographic and polarimetric) evidence on an ability of R and S -α-hydroxybutyric acids, and R and S -m...