Cyclohexane-1,3-dione Oxime Ether Grass-Specific Herbicides and the Discovery of Butroxydim

Abstract

The cyclohexanedione oxime ether herbicides are an important and widely used class of weed-control agents that selectively kill grass species. Since 1975, eight cyclohexanedione herbicides have been commercialized, including six compounds for grass weed control in broad-leaf crops such as cotton, soybeans and vegetables. One cyclohexanedione has been developed for wild oat control in wheat and also one compound for selective removal of barnyard grass in rice. A brief overview of the cyclohexanedione herbicide field is given, together with a more detailed account of the discovery and development of the herbicide butroxydim.

Degradation of Cyclohexanedione Oxime Herbicides

“…These compounds show a keto-enol tautomerism due to the presence of two ketone groups, as well as two isomers E/Z relating to the alkyl side chain bound to oxime ether group. The herbicidal activity of these compounds are mainly due to the cyclohexane-1,3-dione ring and the oxyimino group, although its activity can be increased depending on the different functionalization of the substituents R 1 -R 5 [6,8].…”