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 μg 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.