Whole rye or wheat grains were extracted with acetone at room temperature. The extracts were pooled and acetone was evaporated. The remaining acetone oil was washed out with n-pentane until a colourless filtrate was obtained. The residue was dried, then dissolved in chloroform-acetone (95:5) mixture and separated by column chromatography on silica gel. The fractions containing 5-n-alkylresorcinols were pooled, condensed and crystallised from n-hexane. The preparation obtained was homogeneous in thin-layer chromatography and gave the UV spectrum characteristic for 5-n-alkyl derivatives of resorcinol.