Electrochemically induced cascade Knoevenagel-Michael reactions of tetronic acid and aldehydes: synthesis of methylenebistetronic acids

The results of cascade Knoevenagel-Michael reactions of tetronic acid and various aldehydes induced by electrochemically-generated base are described. It has been observed that electrochemical method at 0 degrees C gave higher yields of the corresponding methylenebistetronic acids. Also, a wide spectra of products could generate from electrolysis at room temperature, including seven-membered cyclic acetals, dehydrodimer of tetronic acid and the desired methylenebistetronic acids. The electrochemical results were also evaluated and compared with those obtained by using a conventional chemical method.