CHIRAL XENOBIOTICS AND NATURAL HALOGENATED COMPOUNDS Isolation of pure enantiomers of Toxaphene congeners via hydrochlorination and chlorination of Pinene and composition of Soviet Polychloropinene

ORGANOHALOGEN COMPOUNDS – Volume 66 (2004) 456 Introduction Toxaphene is an insecticidal mixture, produced by the controlled photochlorination of camphene. In the USSR similar insecticide – Polychloropinene was produced by chlorination of α-pinene with AIBN (azobisisobutyronitrile) as initiator. Natural camphene occurs in different essential oils in (+)-form as well as (–)-form. Production of artificial camphene starts from natural α-pinene, which is also chiral. All noted types of camphene are used for toxaphene synthesis by different manufacturers. Some congeners in selected samples of technical Toxaphene were shown to have small deviations from racemic distribution. Nevertheless, there is no information about any enantiomerically pure congeners of toxaphene. The amount of Polychloropinene produced in the USSR is estimated to be 160 thousand tons, which is a significant contribution into the total global production. Unfortunately, there is no traceable sample of Soviet Polychloropinene available. In the present work we report on the preparation of artificial model Polychloropinene mixtures with different content of chlorine in an attempt to find the difference between Toxaphene and Soviet Polychloropinene. Another goal of our research project is to prepare pure enantiomers of important Toxaphene congeners, to establish their configuration and thus to provide more opportunities to enantiomerspecific environmental analysis of Toxaphene residues.