title: Synthesis and phytotoxic activity of ozonides.
abstract: The [4 + 3] cycloaddition of the proper furans with the oxyallyl cation, generated in situ from 2,4-dibromopentan-3-one, produced a series of 8-oxabicyclo [3.2.1]oct-6-en-3-ones. Exposure of the oxabicycles to ozone afforded the corresponding 8,9,10,11-tetraoxatricyclo[5.2.1.1 (2,6)]undecan-4-ones in variable yields (7-100%). The phytotoxic properties of these ozonides (or 1,2,4-trioxolanes) and their oxabicycle precursors were evaluated as the ability to interfere with the growth of Sorghum bicolor and Cucumis sativus seedlings. Among oxabicycles, the highest inhibitory activity was shown by compounds possessing a alpha,beta-unsaturated carbonyl moiety. A differential sensitivity of the two crops was evident with ozonides. The most active compounds were also tested against the weed species Ipomoea grandifolia and Brachiaria decumbens. To the best of our knowledge, this is the first article describing ozonides as potential herbicides.
authors.affiliation: Department of Chemistry, Federal University of Viçosa, Avenida P.H. Rolfs, CEP 36570-000, Viçosa, MG, Brazil. lcab@ufv.br
authors.forename: Luiz C A
authors.initials: LC
authors.lastname: Barbosa
authors.forename: Ulisses A
authors.initials: UA
authors.lastname: Pereira
authors.forename: Róbson R
authors.initials: RR
authors.lastname: Teixeira
authors.forename: Célia R A
authors.initials: CR
authors.lastname: Maltha
authors.forename: Sergio A
authors.initials: SA
authors.lastname: Fernandes
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Forlani
mesh_terms: D018553:Cucumis sativus / Q000187:drug effects / Q000528:radiation effects; D006540:Herbicides / Q000138:chemical synthesis / Q000737:chemistry / Q000633:toxicity; D006571:Heterocyclic Compounds / Q000138:chemical synthesis* / Q000737:chemistry / Q000633:toxicity*; D015394:Molecular Structure; D006109:Poaceae / Q000187:drug effects / Q000528:radiation effects; D036226:Seedlings / Q000187:drug effects / Q000528:radiation effects; D045868:Sorghum / Q000187:drug effects / Q000528:radiation effects
chemical_list: C503429:1,2,4-trioxane; D006540:Herbicides; D006571:Heterocyclic Compounds