methanol; silica gel in benzene-d6 heating for 4h at 70°C in an NMR tube; identified by NMR;

in benzene at 70-80 °C; excess of the butadiene applied; react. mechanism discussed; elem. anal.; 1H NMR spectrum; mass spectrum;

in benzene Kinetics; at 70-80 °C; competition experiment; excess of both CH2=CPh-CPh=CH2 and CH2=CHPh applied; react. mechanism discussed; 1H NMR spectrum;