<unk>  is an organochloride originally produced in 1948 by J. Hyman & Co, Denver, as an insecticide.<unk>  is closely related to aldrin, which reacts further to form<unk> . Aldrin is not toxic to insects; it is oxidized in the insect to form<unk>  which is the active compound. Both<unk>  and aldrin are named after the Diels-Alder reaction which is used to form aldrin from a mixture of norbornadiene and hexachlorocyclopentadiene. Originally developed in the 1940s as an alternative to DDT,<unk>  proved to be a highly effective insecticide and was very widely used during the 1950s to early 1970s. Endrin is a stereoisomer of<unk> . However, it is an extremely persistent organic pollutant; it does not easily break down. Furthermore, it tends to biomagnify as it is passed along the food chain. Long-term exposure has proven toxic to a very wide range of animals including humans, far greater than to the original insect targets. For this reason, it is now banned in most of the world. It has been linked to health problems such as Parkinson's, breast cancer, and immune, reproductive, and nervous system damage. It is also an endocrine disruptor, acting as an estrogen and antiandrogen, and can adversely affect testicular descent in the fetus if a pregnant woman is exposed to it.
Dieldrin
Anordrin
Psilocin
Clastogen
Urofollitropin
Endrin
Progestogen 
Progestogen