Acetone cardice → HCID 66833120, compound

Participants

Reaction Steps

While under an argon atmosphere, a solution of benzyl 4-(methoxy(methyl) carbamoyl)piperidine-1-carboxylate (15.0 g, 49.0 mmol) in THF (100 mL) was cooled to −78° C. (dry ice/acetone bath) and treated with 3-butenylmagnesium bromide (250 mL, 0.5 M sol. in THF, 125 mmol, Aldrich) via canula. After the addition was complete, the cooling bath was removed allowing the solution to slowly warm to room temperature. After stirring overnight (16 h), the reaction mixture was quenched with 0.1N HCl (200 mL) and diluted with ethyl acetate (300 mL). After stirring an additional 5 min, the organic phase was separated, washed with saturated sodium bicarbonate (200 mL), dried over MgSO4, filtered and concentrated. Purification by MPLC (100 g column, 20-50% ethyl acetate in heptane) gave benzyl 4-pent-4-enoylpiperidine-1-carboxylate (14.5, 98%) as a colorless oil. 1H NMR (CDCl3, 300 MHz) δ 7.38-7.32 (m, 5H), 5.79 (dddd, J1=17.1 Hz, J2=10.2 Hz, J3=6.9 Hz, J4=6.6 Hz, 1H), 5.12 (s, 2H), 5.02 (dd, J1=17.1 Hz, J2=1.5 Hz, 1H), 4.97 (dd, J1=10.2 Hz, J2=1.5 Hz, 1H), 4.28-4.10 (m, 2H), 2.86 (br t, J=12 Hz, 2H), 2.58-2.43 (m, 3H), 2.35-2.28 (m, 2H), 1.9-1.74 (m, 2H), 1.62-1.48 (m, 2H). ESI MS found for C18H23NO3 m/z [302.3 (M+1), 324.1 (M+23)].

Provenance & Evidence