13C NMR (125 MHz, CDCl3) δ 162.8, 155.7, 155.5, 153.2, 152.9, 149.6, 149.1, 149.0, 140.2, 139.7, 133.0, 125.0, 120.4, 120.3, 116.2, 114.7, 109.9, 90.6, 87.4, 84.5, 84.5 (2C), 84.3, 82.6, 82.5, 69.9, 69.6, 61.6, 50.2, 47.2, 27.3, 26.2, 25.9, 25.4, 18.6, 18.2, −4.4, −4.7, −5.3.