反应详情

Potassium bis(trimethylsilyl)amide (31.7 mL, 15.9 mmol) was added dropwise to a solution of t-butanol in anhydrous tetrahydrofuran under nitrogen at room temperature. After 30 min, a solution of cis-methyl 2-(dibenzylamino)cycloheptanecarboxylate (1.33 g, 3.78 mmol) in 50 mL anhydrous tetrahydrofuran was added dropwise via syringe. The reaction was stirred for 17 h and then was partitioned between 250 mL diethyl ether and 200 mL brine. The organic layer was concentrated and purified by flash chromatography on 120 g silica gel with 2 to 4% ethyl acetate in hexane to yield trans-methyl 2-(dibenzylamino)cycloheptanecarboxylate (895 mg, 67%). 1H NMR (400 MHz, CDCl3) δ ppm 7.23-7.30 (8H, m), 7.16-7.22 (2H, m), 3.77 (2H, d, J=13.60 Hz), 3.51 (3H, s), 3.26 (2H, d, J=13.35 Hz), 3.02 (1H, ddd, J=11.08, 8.81, 2.77 Hz), 2.77 (1H, ddd, J=11.02, 6.99, 4.41 Hz), 1.88-1.99 (1H, m), 1.28-1.83 (9H, m).

1. customwas partitioned between 250 mL diethyl ether and 200 mL brine
2. concentrationThe organic layer was concentrated
3. custompurified by flash chromatography on 120 g silica gel with 2 to 4% ethyl acetate in hexane