反应详情

温度

65 °C

A solution of ethyl 2-(benzyloxycarbonylamino)-2-formyl-6-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)hexanoate (0.503 g, 1.13 mmol), piperidine (0.39 mL, 4 mmol) and acetic acid (0.23 mL, 4 mmol) in 1,2-dichloroethane (20 mL) was stirred for 15 minutes then treated with sodium triacetoxyborohydride (0.85 g, 4 mmol). After stirring for 2 h at 65° C. the solution was cooled to room temperature and concentrated. The resulting residue was purified using a combiflash system (12 g silica gel column, 10-100% ethyl acetate in heptanes) to give ethyl 2-(benzyloxycarbonylamino)-2-(piperidin-1-ylmethyl)-6-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)hexanoate (300 mg, 52%). 1H NMR (CDCl3) δ: 7.36 (m, 5H), 6.05 (bs, 1H), 5.14 (d, 1H), 5.03 (d, J=11.2 Hz, 1H), 4.19 (m, 2H), 3.06 (d, J=13.8 Hz, 1H,), 2.59 (d, J=13.8 Hz, 1H), 2.34 (m, 4H), 2.15 (m, 1H), 1.78-1.70 (m, 1H), 1.45-1.25 (m, 12H), 1.22 (s, 12H), 1.02 (m, 1H), 0.73 (t, J=7.8 Hz, 2H). MS found for C28H45BN2O7 m/z[517(M+1)].

1. temperaturewas cooled to room temperature
2. concentrationconcentrated
3. customThe resulting residue was purified