¹H NMR (400 MHz, CDCl₃) δ 6.85 (s, 2H), 5.00 (t, J = 5.0 Hz, 1H), 4.07 – 3.92 (m, 2H), 3.86 – 3.73 (m, 2H), 3.03 (d, J= 5.0 Hz, 2H), 2.34 (s, 6H), 2.25 (s, 3H). ¹³C NMR (101 MHz, CDCl₃) δ 137.25, 135.91, 130.07, 128.94, 104.36, 64.83, 33.91, 20.83, 20.46. HRMS (EI): calcd for C₁₃H₁₈O₂: 206.1307, found: 206.1305。