Abstract
► Ultrasound assisted synthesis of some novel fused pyrans. ► For the same reaction different products are obtained depending on type of catalyst and energy used. ► Sometimes ultrasound irradiations change the reaction path in comparing with silent condition. ► Improvements in rates and yield of reactions are observed under sonication.
Novel fused pyrans were synthesized from the reaction of the tetrahydropyran-4-one with arylidine malononitriles. Different fused pyran derivatives were obtained from the mentioned reaction depending on type of catalyst used and type of energy used. Reactions were carried out under silent and ultrasonic conditions. In general, it was found that sometimes ultrasound irradiations change the reaction path in comparing with silent condition. In addition to improvement in reaction times, the products were obtained in high yields and their structures were determined by elemental analyses, spectral data.