1H NMR (500 MHz, CDCl3) δ 8.30 (s, 1H), 8.29 (s, 1H), 8.16 (br. s, 1H), 7.82 (s, 1H), 7.67 (m, 2H), 7.57–7.43 (m, 2H), 6.16–5.90 (m, 5H), 5.88 (s, 1H), 5.27 (br. s, 1H), 4.94 (dd, J = 6.7 Hz, J = 3.7 Hz, 1H), 4.52 (t, J = 5.4 Hz, 1H), 4.42 (dt, J = 8.7 Hz, J = 4.2 Hz, 1H), 4.20 (dd, J = 4.7 Hz, J = 3.1 Hz, 1H), 4.07 (dt, J = 6.1 Hz, J = 3.0 Hz, 1H), 3.99 (dd, J = 11.5 Hz, J = 3.4 Hz, 1H), 3.92–3.44 (m, 10H), 1.54 (s, 3H), 1.32 (s, 3H), 0.921 (br. s, 9H), 0.918 (br. s, 9H), 0.15–0.05 (m, 12H).