Synthesis, spectral studies, antimicrobial, antioxidant and insect antifeedant activities of some 9H-fluorene-2-yl keto-oxiranes

► Thirteen ee (αS, βR) 9H-fluorene keto-oxiranes were synthesized using phase transfer catalyst. ► Spectral linearity of keto-oxiranes with their spectral data using Hammett equation was studied. ► Antimicrobial activities of all keto-oxiranes using Kirby-Bauer method were studied. ► Antioxidant activities of all keto-oxiranes using DPPH method were studied. ► Insect antifeedant activities of all keto-oxiranes were measured using castor leaf disc-Dethlers method.