¹H NMR (400 MHz, CDCl₃) δ 8.01 (d, J = 7.4 Hz, 2H), 7.59 (t, J = 7.2 Hz, 1H), 7.50 (t, J = 7.3 Hz, 2H), 7.23 (d, J = 6.0 Hz, 3H), 7.08 (d, J = 5.0 Hz, 1H), 6.17 (s, 1H), 3.62 (d, J = 9.8 Hz, 1H), 2.60 (s, 2H), 2.50 (dd, J = 33.8, 14.0 Hz, 2H), 2.38 (s, 3H), 2.19 (d, J = 12.9 Hz, 1H), 1.89 (dd, J = 14.2, 6.3 Hz, 1H). 13C NMR (101 MHz, CDCl₃) δ 203.31, 141.79, 137.78, 136.41, 136.34, 132.97, 128.71, 128.34, 128.21, 127.66, 125.91, 122.93, 122.21, 41.35, 28.76, 27.30, 26.31, 21.56. HRMS (EI): called for C₂₀H₂₀O: 276.1514, found: 276.1515.