Synthesis, XRD/HSA-interactions, biological activity, optical and nonlinear optical responses studies of new pyran derivative

•New 4H-pyran compounds have been prepared via cyclocondensation in a single step and identified by XRD.•Experimental XRD data were discussed and explained based on DFT calculations.•Hirshfeld surface and 2D-fingerprint plots support packed crystal lattice.•UV–Vis. and FT-IR electronic and vibrational absorption bands were assigned.•Global reactivity indices and thermodynamic parameters have been explored at CAM-B3LYP /6–311 G (d, p) level.•NLO responses have been calculated in static and dynamic regime.•Biological activities have been predicted by using the PASS software.