“…R f 0.45 (cyclohexane/EtOAc: 5/1); 1 H NMR (400 MHz, CDCl 3 ) δ 9.32 (s, 1H), 8.41–8.36 (m, 1H), 8.20–8.14 (m, 1H), 7.57–7.47 (m, 4H), 7.45–7.38 (m, 2H), 7.37–7.27 (m, 9H), 7.24–7.16 (m, 5H), 7.05–6.98 (m, 2H), 6.67 (s, 1H), 4.98 (d, J = 11.2 Hz, 1H), 4.91 (d, J = 11.2 Hz, 1H), 4.90 (d, J = 10.8 Hz, 1H), 4.72 (d, J = 12.0 Hz, 1H), 4.56 (d, J = 11.0 Hz, 1H), 4.53 (d, J = 12.1 Hz, 1H), 4.52 (d, J = 10.6 Hz, 1H), 4.16–4.09 (m, 1H), 4.00 (d, J = 9.8 Hz, 1H), 3.97–3.90 (m, 2H), 3.89–3.84 (m, 1H), 3.77 (s, 3H), 3.75–3.67 (m, 2H), and 1.82 (s, 3H). The analysis is consistent with the experimental data reported in the literature …”