ORGANIC SPECTROSCOPY INTERNATIONAL: ISOEUGENOL

ISOEUGENOL

(E)-2-Methoxy-4-(prop-1-enyl) phenol (isoeugenol 6): To 8.0 g of ethyleneglicol placed in a three-neck round-bottom flask of 100 mL are added 7.90 g of KOH (134 mmol), and submerged in a sand bath. To the mixture eugenol 5.0 g (30.5 mmol) is added and the system is refluxed at 160 °C for about approximately 5 hours; at this time the reaction is stopped. The excess of KOH is neutralized with 25 mL of a 6 mol L^-1 hydrochloric acid solution, the mixture is extracted with CHCl₃ (2 × 50 mL) and the organic phase is dried with anhydrous Na₂SO₄and the solvent evaporated under vacuum. After chromatographic column purification, 4.25 g of a brown oil was obtained (85%).

IR (film) n_max/cm^-1: 3503 (O-H), 3057 (C=CH-Ar), 3014 (CH=CH), 2936, 2930, 2843, 1603, 1506, 1367, 1030, 963.
¹H NMR (400.1 MHz, CDCl₃): d 1.86 (3H, dd, J 1.5 and 6.6 Hz, CH₃); 3.90 (3H, s, OCH₃); 5.55 (1H, s, OH); 6.08 (1H, dq, J 6.6 and 15.7 Hz, H2'); 6.32 (1H, dd, J 1.5 and 15.7 Hz, H1'); 6.85 (3H, m, H3, H5 and H6).
¹³C NMR (100.6 MHz, CDCl₃): d 18.3 (CH₃); 55.8 (OCH₃); 107.8 (C5); 114.3 (C6); 119.3 (C3); 123.4 (C4); 130.6 (C2); 130.7 (C1); 144.7 (C2'); 146.5 (C1').

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