13C NMR (125 MHz, CDCl3) δ 155.8, 155.7, 153.3, 153.1, 149.7, 149.6, 139.8, 139.4, 120.5, 120.3, 114.8, 90.7, 87.2, 85.8, 85.1, 83.9, 82.6, 82.4, 70.3, 70.13, 62.0, 51.5, 49.5, 27.4, 26.2, 25.8, 18.6, 18.2, −4.5, −4.8, −5.2, −5.3.