¹H NMR (400 MHz, CDCl₃) δ 8.80 (s, 1H), 8.42 (d, J = 8.1 Hz, 1H), 8.31 (d, J = 7.7 Hz, 1H), 7.70 (t, J = 7.9 Hz, 1H), 7.40 (d, J = 7.6 Hz, 2H), 7.33 (t, J = 7.4 Hz, 2H), 7.24 (d, J = 8.2 Hz, 1H), 6.16 (s, 1H), 3.62 (dd, J = 17.7, 6.0 Hz, 1H), 2.61 (s, 2H), 2.51 (dd, J = 27.3, 13.9 Hz, 2H), 2.19 (d, J = 13.7 Hz, 1H), 1.98 – 1.85 (m, 1H). ¹³C NMR (101 MHz, CDCl₃) δ 201.01, 148.60, 141.49, 137.56, 136.47, 133.97, 130.06, 128.38, 127.33, 127.08, 125.09, 123.20, 122.48, 41.61, 28.52, 27.01, 26.05. HRMS (ESI): calcd for C₁₉H₁₈NO₃ [M + H]: 308.1287, found: 308.1284.