Synthesis of 2,4,6-trihydroxy-3-geranyl acetophenone

tHGA was synthesized according to previously described methods (Ismail et al. 2012). First, phloroacetophenone (1.000 g, 6 mmol), geranylbromide (0.876 g, 4.80 mmol) and anhydrous potassium carbonate (0.415 g, 3.00 mmol) were mixed well in dry acetone (3.5 mL) and then refluxed for 6 h. Then, the reaction mixture was filtered and evaporated under reduced pressure to give an oily orange residue. This residue was later purified via flash column chromatography on Sigel (petroleum ether:EtOAc, 10:1) to produce tHGA in the form of a light yellow powder; mp 128–130 °C. ¹H NMR (CD₃OD), δ_H 1.58 (3H, s, Me), 1.63 (3H, s, Me), 1.76 (3H, s, Me), 2.64 (3H, s, COMe), 1.96 (2H, q, J = 7.5 Hz), 2.06 (2H, m), 3.21 (2H, d, J = 6.5 Hz), 5.08 (1H, t, J = 7 Hz), 5.20 (1H, t, J = 6.5 Hz), 5.92 (1H, s, ArH); IR (KBr) ν_max 3405 and 1627 cm^–1; EIMS m/z (%) [M] + 304 (38), 289 (3), 261 (9), 235 (25), 181 (100). The purity of tHGA was noted as more than 99%.