Effect of the double bond pi-conjugation of the aromatic group of racemic analytes on the liquid chromatographic separation of enantiomers.

Various arylcarbinol esters were resolved on a commercial chiral column, (S, S) Whelk-O1. Among others, the analytes in which the aryl group is in conjugation with the double bond(s) to the chiral center were resolved much better on (S, S) Whelk-O1 than the corresponding non-double bonded analytes. From these results, it was proposed that the double bond pi-conjugation of the aromatic group of racemic analytes is very important for the chiral recognition. In addition, the size of the acyl group of arylcarbinol esters has been demonstrated to be important for the chiral recognition. In general, the large acyl group such as pivaloyl group was very effective for the chiral recognition of arylcarbinol esters on (S, S) Whelk-O1.