13C NMR (125 MHz, DMSO‑d 6) δ 156.2, 156.1, 152.7, 152.6, 149.2, 148.9, 147.7, 139.9, 139.4, 135.9, 133.9, 133.6, 133.3, 133.1, 131.1, 128.9, 128.9, 152.5, 123.3, 121.1, 119.0, 122.0, 121.9, 119.2 (2C), 87.8, 86.3, 85.9, 81.6, 81.5, 72.5, 71.4, 68.8, 67.7, 61.0, 50.0, 47.3.