HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY OF ISOMERIC DIHYDRODIOLS OF POLYCYCLIC-HYDROCARBONS - EFFECT OF CONFORMATION ON ELUTION ORDER

The orders in which K-region and non-K-region dihydrodiols derived from benz[a]anthracene, 7-methylbenz[a]anthracene, 7,12-dimentylbenz[a]anthracene, 3-methylcholantrene, dibenz[a,h]anthracene and benzo[a]pyrene elute from a Partisil 5 column in cyclohexane-ethanol (98:2) have been examined using high-performance liquid chromatography. The elution profiles obtained show that, within a series of dihydrodiols derived from any one hydrocarbon, those trans-dihydrodiols that are known to exist predominantly in a preferred quasi-diequatorial conformation elute much earlier, presumably because of intramolecular hydrogen bonding, than do those that for steric reasons, are known to exist in a predominantly quai-diaxial conformation. These differences appear to be sufficiently large to permit the conformation of an uncharacterized digydrodiol to be predicted from its relative retention time on high-performance liquid chromatography. © 1979.