反应详情

A 50 mL round-bottomed flask was charged with a solution of 3-oxoazetidine-1-carboxylic acid tert-butyl ester (0.57 g, 3.33 mmol), 4-methylpiperidin-4-ol (0.46 g, 3.99 mmol) and 4 Å molecular sieves (3.34 g) in DCE (20 mL). The reaction mixture was stirred for 6 h at room temperature. Sodium triacetoxyborohydride (1.41 g, 6.66 mmol) was added and the reaction mixture was stirred for 18 h at room temperature. The suspension was filtered through Celite and the solution was concentrated in vacuo. The residue was purified by flash chromatography (Si—PPC, EtOAc:cyclohexane, 0:100 to 100:0) to give 3-(4-Hydroxy-4-methylpiperidin-1-yl)azetidine-1-carboxylic acid tert-butyl ester as a colourless oil (0.49 g, 55%). 1H NMR (CDCl3, 400 MHz) δ 3.93 (dd, J=8.7, 7.17 Hz, 2 H); 3.82 (dd, J=8.7, 5.5 Hz, 2 H); 3.15-3.07 (m, 1 H); 2.58-2.44 (m, 2 H); 2.27 (td, J=11.0, 3.5 Hz, 2 H); 1.77-1.54 (m, 4 H); 1.42 (s, 9 H); 1.26 (t, J=6.7 Hz, 3 H).

1. stirringthe reaction mixture was stirred for 18 h at room temperature
2. filtrationThe suspension was filtered through Celite
3. concentrationthe solution was concentrated in vacuo
4. customThe residue was purified by flash chromatography (Si—PPC, EtOAc:cyclohexane, 0:100 to 100:0)