Synthesis of some ۴H-Pyran Derivatives Using Bio-synthesized ZnO Nanoparticles and the Evaluation of their Biological Activities

ZnO Nanoparticles were simply synthesized by green biosynthesis method using ficus carica leaf extract. The structure of these nanoparticles was assigned using Fourier transform infrared spectroscopy (IR), Field emission-scanning electron microscopy (FE-SEM) and X‐ray powder diffraction (XRD). The catalytic activity of these nanoparticles was studied for synthesis of ۴H-pyrans. A series of ۴H-pyrans ۳(a-l) were synthesized in good to high yields by reaction of corresponding α,α′-bis(substituted benzylidene) cycloalkanones and malononitrile in the presence of ZnO nanoparticles as a catalyst at ۱۱۰ ℃. This environmentally friendly method has some advantages such as high efficiency, use of available catalyst, solvent-free reaction conditions and easy operation. The antibacterial activity of synthesized ۴H-pyrans was also tested using Staphylococcus aureus and Escherichia coli bacterial strain.