¹³C NMR (176 MHz, CDCl₃) δ 177.22 (s, 1C), 151.69 (s, 1C), 147.81 (s, 1C), 138.53 (s, 1C), 119.83 (s, 1C), 114.04 (s, 1C), 39.92 (s, 1C), 27.61 (s, 1C).