Dieldrin

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Dieldrin
Dieldrin.svg
IUPAC name (1aR,2R,2aS,3S,6R,6aR,7S,7aS)-3,4,5,6,9,9-hexachloro-1a,2,2a,3,6,6a,7,7a-octahydro-2,7:3,6-dimethanonaphtho[2,3-b]oxirene
Other names Dieldrin
Identifiers
CAS number 60-57-1
KEGG C13718
ChEBI CHEBI:34696
SMILES ClC5(Cl)[C@]3(Cl)C(\Cl)=C(\Cl)[C@@]5(Cl)[C@H]4[C@H]1C[C@H]([C@@H]2O[C@H]12)[C@@H]34
Properties
Molecular formula C12H8Cl6O
Molar mass 380.9 g mol-1
Density 1.75 g/cm³
Melting point

176-177 °C

Boiling point

385 °C

Hazards
MSDS External MSDS
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)

Dieldrin is a chlorinated hydrocarbon originally produced in 1948 by J. Hyman & Co, Denver, as an insecticide. Dieldrin is closely related to aldrin. Aldin reacts further to form dieldrin. Aldrin is not toxic to insects; it is oxidized in the insect to form dieldrin which is the active compound. Both dieldrin and aldrin are named after the Diels-Alder reaction which is used to form aldrin from a mixture of norbornadiene and hexachlorocyclopentadiene.

Dieldrin was developed as an alternative to DDT and has proved to be a highly effective insecticide. It was very widely used during the 1950s to early 1970s. Endrin is a stereoisomer of dieldrin.

However, it is an extremely persistent organic pollutant; it does not degrade easily. 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. For this reason it is now banned in most of the world.

It has been linked to health problems such as Parkinson's disease, breast cancer, and immune, reproductive, and nervous system damage. It can also adversely affect testicular descent in the fetus if a pregnant woman is exposed to Dieldrin.

Dieldrin is listed in the Stockholm Convention on Persistent Organic Pollutants.

Synthesis[change | change source]

It can be formed from the synthesis of hexachloro-1,3-cyclopentadiene with norbornadiene in a Diels-Alder reaction, followed by epoxidation of the norbornene ring.[1]

Synthesis of Dieldrin via a Diels-Alder reaction


Dieldrin is named after Otto Paul Hermann Diels, the co-inventor of the Diels-Alder reaction.

References[change | change source]

  1. Jubb, A. H. (1975). Basic Organic Chemistry, Part 5 Industrial products. London: Wiley. ISBN 0-471-85014-4 .