J = 5.2 Hz, J = 3.8 Hz, 1H), 4.02–3.93 (m, 2H), 3.70–3.48 (m, 4H), 2.86–2.58 (m, 4H). 13C NMR (150 MHz, DMSO‑d 6) δ 156.2, 156.1, 152.6, 152.5,