¹H NMR (400 MHz, CDCl₃) δ 7.33 (s, 4H), 5.58 (s, 1H), 5.14 (s, 1H), 3.62 – 3.45 (m, 2H), 2.77 – 2.61 (m, 2H), 1.89 – 1.70 (m, 6H), 1.30 (s, 9H). ¹³C NMR (101 MHz, CDCl₃) δ 175.64, 151.41, 149.06, 133.16, 125.35, 125.35, 110.22, 51.94, 37.57, 34.46, 31.15, 29.99, 28.68, 23.45. HRMS (EI): calcd for C₁₈H₂₅NO: 271.1936, found: 271.1939。