1H NMR (500 MHz, CDCl3) δ 8.27 (s, 1H), 8.18 (s, 1H), 8.15 (s, 1H), 7.82 (br. s, 2H), 7.29–7.27 (m, 2H), 6.22 (br. s, 2H), 6.20 (br. s, 2H), 6.10 (d, J = 3.6 Hz, 1H), 5.99 (d, J = 2.1 Hz, 1H), 5.37 (dd, J = 6.5 Hz, J = 2.1 Hz, 1H), 4.91 (dd, J = 6.5 Hz, J = 3.7 Hz, 1H), 4.48 (t, J = 5.1 Hz, 1H), 4.30 (td, J = 6.7 Hz, J = 3.6 Hz, 1H), 4.22 (t, J = 4.2 Hz, 1H), 4.07 (dt, J = 5.8 Hz, J = 3.0 Hz, 1H), 3.99 (dd, J = 11.5 Hz, J = 3.4 Hz, 1H), 3.81–3.72 (m, 2H), 3.71–3.66 (m, 1H), 3.65–3.61 (m, 2H), 2.90–2.70 (m, 4H), 1.57 (s, 3H), 1.36 (s, 3H), 0.92 (s, 9H), 0.86 (s, 9H), 0.14 – - 0.02 (m, 12H).