Abstract
Synthesis of 2‐amino‐4‐aryl‐3‐carbalkoxy‐7,7‐dimethyl‐5‐oxo‐5,6,7,8‐tertrahydrobenzo[b]pyran derivatives was carried out in 81–98% yields by one‐pot condensation of aromatic aldehydes with cyanoacetic esters and 5,5‐dimethyl‐1,3‐cyclohexanedione catalyzed by KF/basic Al2O3 at room temperature under ultrasound irradiation.
Acknowledgments
The project was supported by Educational Ministry of China and Natural Science Foundation of Hebei Province (203107), P. R. China.