The kinetics of the reaction between 1-phenyl-4-benzyliden-5-pyrazolone and ethoxyethenes have been studied by quantitative spectroscopic analysis in xylene at various temperatures. These 1, 4-cycloadditions are HOMO-ethoxyethene controlled but Sustmann's approximation of the general perturbation equation cannot be used to rationalize the results since meaningless relationships are obtained by plotting the log of the rate constants vs ...
![3,3-diethoxy-5,9-diphenyl-2-oxa-8,9-diazabicyclo[4.3.0]nona-7,10-diene Structure](https://image.chemsrc.com/caspic/069/85523-01-9.png)