Collect. Czech. Chem. Commun. 1981, 46, 3110-3114

Transmission of polar effects arcoss the CH=CH link in styrylfuran system

Viera Knoppováa, Anton Beňob, Miloslava Dandárováa and Jaroslav Kováča

a Department of Organic Chemistry, Slovak Institute of Technology, 880 37 Bratislava
b Department of Analytical Chemistry, Comenius University, 816 50 Bratislava


Transmission of polar substituent effect through the vinylidene grouping in 5-(4-X-styryl)-2-furaldehydes (X = H, Cl, Br, COOCH3, CN and NO2) was studied by polarographic reduction of the aldehyde group as well as by kinetics of their condensation with malononitrile. The obtained transmission coefficients π' were compared with the corresponding values for systems, containing other links between the benzene and furan nuclei. Thermodynamic parameters of the condensation with malononitrile were determined. The transmission of polar effects is discussed also from the point of view of 1H NMR spectra.