1H NMR (400 MHz, DMSO) δ 6.47 (dd, 1 H, J = 6.8, 14.4 Hz), 4.20 (dd, 1 H, J = 1.9, 14.4 Hz), 4.00 (dd, 1 H, J = 1.9, 6.8 Hz), 3.77 (q, 2 H, J = 7.0 Hz), 1.31 (t, 3 H, J = 7.0 Hz).