반응 단계
A solution of [6]-shogaol (138 mg, 0.5 mmol) in methanol (10 mL) was cooled to −78° C., CeCl3.7H2O (745 mg, 2.0 mmol) was added and the mixture was stirred at −78° C. for 10 min. Then, NaBH4 (48 mg, 1.25 mmol) was added to the mixture and allowed to react at −78° C. for 30 min. The reaction was quenched by saturated aqueous NH4Cl solution (20 mL) and extracted with ethyl acetate (20 mL×3). The organic phases were separated, pooled, washed with water (10 mL×2) and brine (10 mL×1), dried over Na2SO4, and evaporated in vacuo. The residue was subjected to preparative TLC (hexane/EtOAc=3:1) to produce the title compound M6 as a colorless oil (139 mg, yield 100%); 1H NMR (600 MHz, CDCl3) δ 6.70 (1H, d, J=1.7 Hz, H-2′), 6.82 (1H, d, J=8.0 Hz, H-5′), 6.68 (1H, dd, J=8.0, 1.7 Hz, H-6′), 2.62 (2H, m, H-1), 1.85 (1H, m, H-2a), 1.78 (1H, m, H-2b), 4.07 (1H, m, H-3), 5.49 (1H, dd, J=15.3, 6.7 Hz, H-4), 5.65 (1H, dt, J=15.3, 6.7 Hz, H-5), 2.03 (2H, m, H-6), 1.38 (2H, m, H-7), 1.32-1.25 (4H, m, H-8 and H-9), 0.89 (3H, t, J=6.9 Hz, H-10), and 3.87 (3H, s, OMe-3′); positive APCIMS: m/z 279 [M+H]+.
