“…1f was prepared by monobenzylation of 2,4-dihydroxybenzaldehyde followed by Horner–Wittig reaction. Recrystallization from EtOH/H 2 O; light-yellow solid, 757 mg (56%), mp 188–190 °C; 1 H NMR (400 MHz, acetone- d 6 ) δ 10.44 (br s, 1H), 9.15 (s, 1H), 7.94 (d, J = 16.0 Hz, 1H), 7.32–7.56 (m, 6H), 6.60–6.62 (m, 2H), 6.47 (d, J = 16.0 Hz, 1H), 5.13 (s, 2H); 13 C NMR (100 MHz, acetone- d 6 ) δ 168.7, 162.7, 158.9, 141.0, 138.0, 131.1, 129.4, 128.8, 128.5, 116.2, 115.9, 108.1, 103.3, 70.6; HRMS (ESI) m / z [M + H] + calcd for C 16 H 15 O 4 271.0965, found 271.0960.…”