1H NMR (400 MHz, CDCl3) δ: 7.97 (d, J = 7.7 Hz, 2H), 7.54 – 7.58 (m, 1H), 7.44 – 7.48 (m, 2H), 4.44 – 4.38 (m, 1H), 3.91– 3.87 (dd, J = 14.6, 7.2 Hz, 1H), 3.76 – 3.75 (dd, J = 14.8, 7.4 Hz, 1H), 3.43 – 3.37 (dd, J = 16.3, 6.1 Hz, 1H), 3.09 – 3.03 (dd, J = 16.3, 6.7 Hz, 1H), 2.23 – 2.16 (dt, J = 13.0, 6.5 Hz, 1H), 1.98 – 1.88 (m, 2H), 1.61 – 1.52 (m, 1H). 13C NMR (100 MHz, CDCl3) δ: 25.6, 31.6, 44.6, 67.8, 75.4, 128.2, 128.6, 133.1, 137.0, 198.4.