The general procedure for the synthesis of 4-isopropylresorcinol from (((4-(1-propen-2-yl)-1,3-phenylene)bis(oxy))bis(methylene))bis(benzene))diphenyl was as follows: a mixture of compound 17 (3 g, 9.08 mmol) with 10% Pd/C (30 wt%) in ethanol (48 mL) was placed in a hydrogen atmosphere and stirred for 18 hours at room temperature. Upon completion of the reaction, the solid catalyst was removed by filtration through a diatomaceous earth pad and the filter cake was washed with methanol. The filtrate was concentrated under reduced pressure and the resulting crude product was purified by silica gel fast column chromatography (eluent ratio: ethyl acetate:hexane=1:1) to afford compound 18 as a white crystalline solid (1.35 g, 98% yield). The physical and spectral data of the compound were consistent with those reported in the literature: melting point 87~89 °C. 1H NMR (400 MHz, DMSO-d6) δ 9.02 (s, 1H), 8.90 (s, 1H), 6.85 (d, J=8.2 Hz, 1H), 6.26 (d, J=2.7 Hz, 1H), 6.16 (dd, J=8.2,2.3 Hz , 1H), 3.16-2.98 (m, 1H), 1.18-1.04 (s, 6H); 13C NMR (100 MHz, DMSO-d6) δ 155.59,154.78,125.87,124.56,105.67,102.11,25.52,22.64. ESI-MS: m/z = 170 (M +H2O)+.
