Molecular structure of 4-hidroxy-3-(3-methyl-2-butenyl) acetophenone, a plant antifungal, by X-ray diffraction, DFT calculation, and NMR and FTIR spectroscopy

► The crystal structure of the title compound has been solved by X-ray diffraction. ► The solid has two mixed and closely related conformers with unequal occupancies. ► Strong intermolecular OH⋯O bonds give rise to a polymeric structure in the lattice. ► The crystallographic data affords a complete assignment of FTIR and Raman spectra. ► The observed and calculated 1H and 13C NMR chemical shifts are in close agreement.