QUANTITATIVE STRUCTURE ELECTROCHEMISTRY RELATIONSHIPS OF ALPHA,BETA-UNSATURATED KETONES

The half-wave potential (E(1/2)) of 26 substituted alpha,beta-unsatura ted ketones in non-aqueous acetonitrile were used in Hammett type quan titative structure-activity relationship (QSAR) analysis. A linear rel ationship between E(1/2) and the electronic substituent constant, sigm a(X) and reaction constant rho(R) was revealed for 17 substituted chal cones. Linear regression equations were calculated using only the sum of sigma(X,para) + sigma(X,meta) of all substituents. It was found tha t the production of the substituted 1,2-oxaphosphol-4-en in the redox reaction of the alpha, beta-unsaturated ketones and trialkyl phosphite can be predicted from the E(1/2) values of the alpha,beta-unsaturated ketones measured in nonprotic solvent. The E(1/2) values also give a linear correlation with the conversions of the starting ketones.