Pinacolone Explained

Pinacolone (3,3-dimethyl-2-butanone) is an important ketone in organic chemistry. It is a colorless liquid with a slight peppermint or camphor odor. It is a precursor to triazolylpinacolone in the synthesis of the fungicide triadimefon and in synthesis of the herbicide metribuzin. The molecule is an unsymmetrical ketone. The α-methyl group can participate in condensation reactions. The carbonyl group can undergo the usual reactions (hydrogenation, reductive amination, etc.). It is a Schedule 3 compound under the Chemical Weapons Convention 1993, due to being related to pinacolyl alcohol, which is used in the production of soman.[1] It is also a controlled export in Australia Group member states.[2]

Preparation

Most famously, at least in the classroom, pinacolone arises by the pinacol rearrangement, which occurs by protonation of pinacol (2,3-dimethylbutane-2,3-diol).

Industrially pinacolone is made by the hydrolysis of 4,4,5-trimethyl-1,3-dioxane, which is the product of isoprene and formaldehyde via the Prins reaction. It also is generated by ketonization of pivalic acid and acetic acid or acetone over metal oxide catalysts. 3-Methylbutanal is a starting material for 2,3-dimethyl-2-butene, which in turn is converted to pinacolone. Pinacolone can also be produced from 2-methy-2-butanol when reacted with C5 alcohols.[3]

Uses

Pinacolone is produced in large amounts for use in fungicides, herbicides, and pesticides. Some derivatives include:

See also

Notes and References

  1. Book: Handbook of chemical and biological warfare agents . 24 August 2007 . CRC Press . 9780849314346 . 2nd.
  2. Web site: Export Control List: Chemical Weapons Precursors. Australia Group. australiagroup.net. 7 April 2017. 4.
  3. Book: Siegel, H. Eggersdorfer . Ketones. Ullman's Encyclopedia of Industrial Chemistry. 2012. 20. 5. 6. 10.1002/14356007.a15_077. 9783527306732.
  4. Oda . T . Sato . Y . Kodama . M . Kaneko . M . Inhibition of DNA topoisomerase I activity by diethylstilbestrol and its analogues. . Biological & Pharmaceutical Bulletin . July 1993 . 16 . 7 . 708–10 . 8401407 . 10.1248/bpb.16.708. free .