Synthesis, crystal structure and herbicidal activity of mimics of intermediates of the KARI reaction.

Two mimics of the intermediate in the reaction catalyzed by ketol-acid reductoisomerase (KARI) were synthesized. Their structures were established on the basis of elemental analyses, IR, 1H NMR and GC/mass detector. The crystal structure of compound 2 was found to be a substituted dioxane, formed by the condensation of two molecules. The two compounds showed some herbicidal activity on the basis of tests using rape root and barnyard grass growth inhibition. However, the herbicidal effect was weaker in greenhouse tests.