Reaktionsschritte
[6]-Shogaol (276 mg, 1.0 mmol) was dissolved in tetrahydrofuran (THF) and cooled down to 0° C. To this mixture, a solution of DDQ (181 mg, 0.8 mmol) in THF was added. The mixture was stirred at 0° C. for 30 minutes and then warmed to room temperature (RT) for 3 hours. Then water was added and the resulting mixture was extracted with EtOAc (×3). The organic phase was washed with water (×1) and brine (×1), dried over anhydrous NaSO4, and filtered. The filtration was evaporated and the residue was purified by chromatography column (CC) (hexane/ethyl acetate=8:1 and 6:1) to give the desired compound as a yellow oil (170 mg, yield: 62%); 1H NMR (600 MHz, CDCl3) δ 7.59 (1H, d, J=15.9 Hz, H-1), 6.82 (1H, d, J=15.9 Hz, H-2), 6.44 (1H, d, J=15.6 Hz, H-4), 6.99 (1H, dt, J=15.6, 7.0 Hz, H-5), 2.27 (2H, q, J=7.0 Hz, H-6), 1.51 (2H, m, H-7), 1.34-1.29 (4H, m, H-8 and H-9), 0.90 (3H, t, J=6.8 Hz, H-10), 7.07 (1H, d, J=1.4 Hz, H-2′), 6.93 (1H, d, J=8.2 Hz, H-5′), 7.14 (1H, dd, J=8.2, 1.4 Hz, H-6′), and 3.93 (3H, s, OMe-3′); 13C NMR (150 MHz, CDCl3) δ 143.3 (d, C-1), 123.3 (d, C-2), 189.3 (s, C-3, C═O), 129.1 (d, C-4), 148.0 (d, C-5), 32.7 (t, C-6), 27.9 (t, C-7), 31.4 (t, C-8), 22.4 (t, C-9), 14.0 (q, C-10), 127.4 (s, C-1′), 109.7 (d, C-2′), 148.1 (s, C-3′), 146.8 (s, C-4′), 114.8 (d, C-5′), 122.9 (d, C-6′), and 56.0 (q, OMe-3′); positive ESI-MS, m/z 275 [M+H]+.
