1H NMR (500 MHz, CDCl3) δ 8.32 (s, 1H), 8.29 (s, 1H), 8.12 (s, 1H), 7.81 (s, 1H), 7.59–7.46 (m, 2H), 7.34–7.22 (m, 2H), 5.97 (d, J = 3.3 Hz, 1H), 5.96–5.88 (m, 5H), 5.41 (dd, J = 6.4 Hz, J = 2.0 Hz, 1H), 5.07 (dd, J = 6.4 Hz, J = 3.5 Hz, 1H), 4.50 (dd, J = 5.9 Hz, J = 4.6 Hz, 1H), 4.46–4.34 (m, 1H), 4.21 (dd, J = 4.7 Hz, J = 3.3 Hz, 1H), 4.03 (dt, J = 6.0 Hz, J = 3.0 Hz, 1H), 3.98 (dd, J = 11.4 Hz, J = 3.5 Hz, 1H), 3.80–3.72 (m, 3H), 3.68 (dd, J = 14.6 Hz, J = 5.6 Hz, 1H), 3.46–3.31 (m, 3H), 1.57 (s, 3H), 1.36 (s, 3H), 0.91 (s, 9H), 0.89 (s, 9H), 0.11–0.03 (m, 12H).