The Absolute Configuration of (+)-α-1,2,3,4,5,6-Hexachlorocyclohexane, and Its Permeation through the Seal Blood-Brain Barrier

Not the result of enzymatic degradation processes, but of the “preferential permeability” of the blood–brain barrier for (+)‐α‐hexachlorocyclohexane (HCH)—this is the interpretation of the selective accumulation of this enantiomer in seal brain. This conclusion could be drawn only after the α‐HCH isomers were successfully separated on a chiral phase by HPLC. The structure of the (+) enantiomer was determined by X‐ray crystallography, but the structural elements responsible for the selective transfer are still unknown.