Resolution of enantiomeric triols, triol-hydroxyethylthioethers, and methoxy-triols derived from three benzo[a]pyrene diol-epoxides by chiral stationary phase high-performance liquid chromatography

Benzoa]pyrene 7,8-diol-anti-9,10-epoxide, 7,8-diol-syn-9,10-epoxide, and 9,10-diol-anti-7,8-epoxide were converted to triol, triol-hydroxyethylthioether, and methoxy-triol derivatives. Enantiomeric pairs of these derivatives were resolved by high-performance liquid chromatography with Pirkle's pi-electron acceptor chiral stationary phases. Resolution of enantiomers was confirmed by ultraviolet-visible absorption, circular dichroism, and mass spectral analyses. Relative to those of tetrols, these derivatives are less polar and have shorter retention times and improved enantiomeric resolution on chiral stationary phases. Absolute stereochemistries of most enantiomeric derivatives were deduced by comparing their circular dichroism spectra to those of similar compounds derived from enantiomeric diol-epoxides of known absolute stereochemistry.