New 8-oxabicyclo[3.2.1]oct-6-en-3-one derivatives with plant growth regulatory activity

Several 8-oxabicyclo[3.2.1]oct-6-en-3-one derivatives have been prepared via the [3 + 4] cycloaddition between the oxyallyl carbocation generated from polybromoketones and alkylfurans. The selective effects of these compounds on the radicle growth of a monocotyledon [sorghum (Sorghum bicolor L.)] and a dicotyledon [cucumber (Cucumis sativus L.)] were evaluated. All of the test compounds, at the concentration of 100 mu g mL(-1), stimulated cucumber root growth (5-30%), but they inhibited sorghum root growth (23-56%). None of the compounds had any effect on the percent of germination of the species tested.