Coelhan Mehmet, Maurer Martin
Research Center for Brewing and Food Quality, Technical University of Munich, 85350 Freising-Weihenstephan, Germany.
J Agric Food Chem. 2005 Dec 28;53(26):10105-12. doi: 10.1021/jf051451b.
The synthesis of 2-endo,3-exo,5-endo,6-exo,8,9,10-heptachlorobornane (B7-1001, Hp-Sed) and 2-endo,3-exo,5-endo,6-exo,8,9,9,10-octachlorobornane (B8-1412) is described. Both compounds are components of toxaphene, an insecticide that has been widely used in the past. B7-1001 is an important toxaphene congener, comprising up to 99% of total toxaphene concentrations found in fish and sediment samples from treated lakes. B8-1412 is also a significant component of toxaphene contamination in samples from biota. In synthesizing the compounds, 2-exo,3-endo,6-endo,8,9,10-hexachlorobornane (B6-913) was obtained by reduction of the well-known toxaphene component P 32 (B7-515, 2,2,5-endo,6-exo,8,9,10-heptachlorobornane), which was itself isolated from the chlorination products of (+)-camphene. Chlorination of B6-913 provided B7-1001 in 49.5% yield, and P 32 and four other heptachlorobornanes were also detected in the reaction mixture. Structures of two of the heptachlorobornanes were elucidated by MS and NMR as 2-exo,3-endo,6-endo,8,9,9,10-heptachlorobornane (B7-1461) and 2-exo,3,3,6-endo,8,9,10-heptachlorobornane (B7-1303). B8-1412 was isolated from the product mixture obtained by chlorination of 2-exo,3-endo,6-endo,8,9,9,10-heptachlorobornane. Photolysis experiments at lambda = 254 nm revealed that B6-913 is photochemicaly the most stable compound of the seven toxaphene compounds studied, with a t(1/2) of 213 h. B7-1001, having a t(1/2) of 82 h, was the second most stable compound. B8-1412 was degraded more rapidly, with a t(1/2) of 28.8 h, than B7-1001, but was still much more stable than P 50 (B9-1679, 2-endo,3-exo,5-endo,6-exo,8,8,9,10,10-nonachlorobornane), which had a t(1/2) of 9.4 h, despite its reputation as a very persistant compound. Under the same experimental conditions hexachlorobenzene (HLB) and octachlorodibenzodioxine (OCDD) were consumed very quickly with t(1/2) = 0.0025 and 0.0015 h, respectively.
描述了2-内型，3-外型，5-内型，6-外型，8,9,10-七氯冰片烷（B7-1001，Hp-Sed）和2-内型，3-外型，5-内型，6-外型，8,9,9,10-八氯冰片烷（B8-1412）的合成。这两种化合物都是毒杀芬的成分，毒杀芬是一种过去曾被广泛使用的杀虫剂。B7-1001是一种重要的毒杀芬同系物，在来自经处理湖泊的鱼类和沉积物样品中，其在毒杀芬总浓度中所占比例高达99%。B8-1412也是生物群样品中毒杀芬污染的重要成分。在合成这些化合物时，通过还原著名的毒杀芬成分P 32（B7-515，2,2,5-内型，6-外型，8,9,10-七氯冰片烷）得到了2-外型，3-内型，6-内型，8,9,10-六氯冰片烷（B6-913），P 32本身是从（+）-莰烯的氯化产物中分离得到的。B6-913的氯化反应以49.5%的产率得到了B7-1001，并且在反应混合物中还检测到了P 32和其他四种七氯冰片烷。通过质谱和核磁共振确定了其中两种七氯冰片烷的结构，分别为2-外型，3-内型，6-内型，8,9,9,10-七氯冰片烷（B7-1461）和2-外型，3,3,6-内型，8,9,10-七氯冰片烷（B7-1303）。B8-1412是从2-外型，3-内型，6-内型，8,9,9,10-七氯冰片烷的氯化产物混合物中分离得到的。在λ = 254 nm下的光解实验表明，B6-913是所研究的七种毒杀芬化合物中光化学性质最稳定的化合物，半衰期为213小时。半衰期为82小时的B7-1001是第二稳定的化合物。B8-1412的降解速度比B7-1001更快，半衰期为28.8小时，但仍比P 50（B9-1679，2-内型，3-外型，5-内型，6-外型，8,8,9,10,10-九氯冰片烷）稳定得多，尽管P 50素有非常持久的化合物之名，但其半衰期为9.4小时。在相同的实验条件下，六氯苯（HCB）和八氯二苯并二恶英（OCDD）的消耗速度非常快，半衰期分别为0.0025小时和0.0015小时。
