反应详情

Carboxylic acid 14 (544.4 mg, 1.81 mmol) was placed in 1:1 CH3OH-toluene (6 mL) under N2, and trimethylsilyldiazomethane (2 M solution in hexane, 4.0 mL, 8.0 mmol) was added. The solution was stirred at ambient temperature for 16 h. The solvent was evaporated, and the residue was chromatographed (silica gel, 17 g; 9:1 hexane-EtOAc) to yield 0.46 g (81%) of 15 as a colorless oil: Rf0.54 (4:1 hexane-EtOAc); 1H NMR δ 7.33 (5H, m), 6.48 (1H, br d), 5.34 (1H, s), 5.11 (1H, d, J=0.8 Hz), 4.64 (1H, dd, J=8.7 and 4.0 Hz), 3.76 (3H, s), 3.48 (1H, m), 1.26 (3H, d, J=7.1 Hz).

1. customThe solvent was evaporated
2. customthe residue was chromatographed (silica gel, 17 g; 9:1 hexane-EtOAc)