反应详情

To a solution of L-valine methyl ester hydrochloride (633 mg, 3.78 mmol), (1R,3S,4S)-3-methoxy-4-(nitrooxy)cyclopentanecarboxylic acid (755 mg, 3.78 mmol), and triethylamine (1.05 mL, 7.55 mmol) in dichloromethane (30 mL) was added PyBOP (2.95 g, 5.67 mmol). After stirring at rt overnight, the mixture was washed saturated NaHCO3 (3×50 mL) and brine (50 mL), dried over MgSO4, and concentrated. The residue was purified by flash chromatography (RediSepRf 80 g) using 0-40% EtOAc/hexane gradient, affording the title compound (1.04 g, yield 86%): 1H NMR (500 MHz, CDCl3) δ 6.50 (d, J=8.6, 1H), 5.40 (d, J=6.0, 1H), 4.55 (dd, J=4.7, 8.8, 1H), 3.92 (m, 1H), 3.77 (s, 3H), 3.47 (s, 3H), 2.96-2.91 (m, 1H), 2.52-2.46 (m, 1H), 2.38-2.32 (m, 1H), 2.24-2.17 (m, 2H), 2.07-2.01 (m, 1H), 0.97 (d, J=6.9, 3H), 0.92 (d, J=6.9, 3H).

1. washthe mixture was washed saturated NaHCO3 (3×50 mL) and brine (50 mL)
2. dry with materialdried over MgSO4
3. concentrationconcentrated
4. customThe residue was purified by flash chromatography (RediSepRf 80 g)