¹H NMR (400 MHz, CDCl₃) δ 7.53 – 7.50 (dd, J = 7.1, 4.5 Hz, 3H), 7.38 – 7.24 (m, 7H), 7.14 – 7.10 (m, 1H), 6.99 (d, J= 7.4 Hz, 1H), 6.82 – 6.79 (m, 1H), 6.70 (d, J = 7.9 Hz, 1H), 4.99 (d, J = 15.7 Hz, 1H), 4.79 (d, J = 15.8 Hz, 1H), 3.93 (d, J = 14.5 Hz, 1H), 3.75 (d, J = 14.6 Hz, 1H), 1.44 (s, 3H); ¹³C NMR (100 MHz, CDCl₃) δ: 25.9, 44.1, 45.6, 61.5, 109.4, 122.4, 123.8, 127.2, 127.5, 127.6, 128.3, 128.7, 128.8, 129.4, 133.3, 135.7, 140.0, 142.3, 177.7; HRMS (EI) m/z calcd for C₂₃H₂₁NO₃S [M⁺]: 391.1242; found, 391.1238.