
%0 Journal Article
%A Barbosa, Luiz Cl&aacute;udio de A. 
%A Concei&ccedil;&atilde;o, Gelson J. A. 
%A Demuner, Ant&ocirc;nio J. 
%A Silva, Ant&ocirc;nio A. 
%A Mann, John 
%A Pil&oacute;-Veloso, Dorila 
%T A New Class of Herbicides that are Derivatives of 8-Oxabicyclo[3.2.1]oct-6-en-3-one
%J Australian Journal of Chemistry
%D 1999/12/03
%V 52
%N 10
%P 929-936
%K 
%R https://doi.org/10.1071/CH99044
%U https://www.publish.csiro.au/paper/CH99044 
%X Treatment of 8-oxabicyclo&#91;3.2.1&#93;oct-6-en-3-one with a catalytic amount of osmium tetraoxide and excess hydrogen peroxide resulted in the formation of the acetonide exo-6,exo-7-isopropylidenedioxy-8-oxabicyclo&#91;3.2.1&#93;oct-3-one (2), in 96% yield. This acetonide was converted into several aromatic alcohols (4a&#8211;k) through a Grignard reaction. The alcohols were treated with aqueous HCl in acetone, and the corresponding alkenes (5a&#8211;c,e&#8211;g, j,k) were obtained in 26&#8211;46% overall yield, from the ketone (2). The herbicidal activity of the alkenes was evaluated at a concentration of 6.6 &#181;g g&#8722;1. All compounds showed an inhibitory effect (21&#8211;66%) on the Sorghum bicolor radicle growth. The inhibition of the accumulation of fresh and dried weight of the aerial parts of Cucumis sativus, after 14 days, varied from 7.1 to 60.7% and from 0.0 to 41.6%, respectively. Compounds (5a,e&#8211;g) caused 100% mortality of C. sativus, after 20 days. Compound (5g) (exo-6,exo-7-isopropylidenedioxy-3-(3-methylphenyl)-8- oxabicyclo&#91;3.2.1&#93;oct-2-ene) was evaluated against several weeds, and it caused 100% mortality of Desmodium tortuosum and Pennisetum setosum. 
