Juglone 1 is a naphthoquinone compound found in the plants of the Fam. Juglandaceae. Especially high amounts can be detected in the eastern black walnut (Juglans nigra) and common walnut (Júglans régia). It is well known that juglone has a broad spectrum of biological activity, including antibacterial and antifungal properties [1]. Juglone is widely used in traditional medicine in the form of tincture, balsam, syrup, as general tonic, immunomodulatory, blood sugar regulatory, hipotensive and antiparasitic remedy. Juglone containing ointments are used as antiinflammatory, antibacterial and antifungal remedies [2]. Anticancer properties have been also detected for juglone by some researchers [3]. The main objective of the present research was investigation of the reaction between 2hydroxy-juglone 1 with perillaldehyde 2 with obtaining of an unusual new derivative of 1,4naphthoquinone 3 (Scheme). Reaction has been performed in the presence of the Hantzsch ester as a reducing agent and L-proline as catalyst. The reaction mechanism included not only methylation but also 1,4-addition.formulaScheme. The synthesis of compound 3.The product was separated with application of the column chromatography. The structure of the obtained compound was confirmed by application of different physico-chemical methods of analysis. The identity of the compounds has been established by various 1H–, 13C–NMR experiments including those bi-dimensional (COSY, HSQC, HMBC, NOE). Also the structure of 3 was confirmed by X-ray analysis.