Direct resolution of some phenylglycines by liquid chromatography on a chiral crown ether phase

The optical resolution of a series of 12 amino acids of the phenylglycine family was studied using a chiral crown ether column. The effects of pH, temperature, and mobile phase additive were investigated. In three examples it was confirmed that the R enantiomer eluted prior to the S enantiomer. Most phenylglycines were resolved with large separation factors; those with two functional groups substituents on opposing sides of the phenyl ring, however, were not well separated.