Menthyl acetate. A new link in the chain of acetates studied with rotational spectroscopy

•Investigation of menthyl acetate, a flexible naturally occurring compound.•Detailed conformational analysis of menthyl acetate using rotational spectroscopy.•Determination of an accurate experimental structure.•Analysis of the splittings arising from a low barrier methyl-top internal rotation.•Comparison with the internal rotation parameters from other low-barrier acetates.