Synthesis and characterization of 2,6-dimethyl-4-p-substituted phenyl-3-cyclohexenecarboxylic acids

CHED 460

Caryn R. O’Hearn, cohearn@iuk.edu and Songwen Xie, soxie@iuk.edu. Department of Natural, Information, and Mathematical Sciences, Indiana University Kokomo, 2300 S Washington St., Kokomo, IN 46904
A few 2,6-dimethyl-4-p-substituted phenyl-3-cyclohexenecarboxylic acids have been synthesized and their structures were characterized by X-ray single crystal analysis. Unlike other chiral carboxylic acids forming RS dimers in the solid state, one of these compounds forms RR and SS dimers, and another one has RS, RR, and SS dimers in the same crystal. The reason for this unusual phenomenon is that the two enantiomers of these carboxylic acids differ from each other only in the position of the double bond in the system. Without the double bond, the molecules will be achiral. So these molecules have a pseudo plane of symmetry, which gives them the tendency of forming solid solutions.