¹³C NMR (176 MHz, CDCl₃) δ 169.63 (s, 1C), 139.10 (s, 1C), 133.59 (s, 1C), 132.45 (q, J = 33.6 Hz, 1C), 129.64 (s, 1C), 129.62 (s, 1C), 128.26 (s, 1C), 123.12 (q, J = 272.8 Hz, 1C), 119.56 (d, J = 2.6 Hz, 1C), 117.85 (m, J = 3.6 Hz, 1C), 44.86 (s, 1C).