反应条件: temp:0.01; pressure:0.00; stir:; See reaction.notes.procedure_details.
实验步骤: A solution of 0.32 mL (2.2 mmol) of diisopropylamine in 10 mL of THF at 0° C. was treated with 0.92 mL (2.3 mmol) of 2.5 M n-butyllithium in sol'n in hexanes. The resulting solution was stirred at 0° C. for 10 min, then cooled to −78° C. A solution of 0.51 g (1.8 mmol) of (1-tert-butoxycarbonylpiperidin-4-yl)acetic acid, ethyl ester (from Piperidine 35, Step A) in 2 mL of THF was added. After stirring for 30 minutes, a solution of 0.26 g (2.1 mmol) 5-chloropentanal in 2 mL of THF was added (J. Org. Chem. 1981, 46, 2007). The reaction was stirred for 1.75 hours at −78° C. and 3.5 hours at 0° C. After quenching the reaction with saturated NH4Cl, volatiles were removed under reduced pressure. The residue was partitioned between 100 mL of Et2O and 100 mL of H2O. After separating phases, the organic layer was washed with 100 mL of 0.5 N HCl and 100 mL of 1 N NaHCO3, dried over MgSO4 and concentrated. The residue was purified with a 40M Biotage column using 3:1 v/v of hexanes/EtOAc as the eluant to afford impure title compound: RF: 0.27 (7:3 v/v hexanes/EtOAc); 1H-NMR (500 MHz) δ 1.24–2.08 (m, 23H), 2.38 (t, J=6.2, 1H), 2.63–2.71 (m, 2H), 3.53–3.56 (m, 2H), 3.92 (m, 1H), 4.09–4.19 (m, 4H).
cooled to −78° C
After stirring for 30 minutes
The reaction was stirred for 1.75 hours at −78° C. and 3.5 hours at 0° C
After quenching
the reaction with saturated NH4Cl, volatiles
were removed under reduced pressure
The residue was partitioned between 100 mL of Et2O and 100 mL of H2O
After separating phases
the organic layer was washed with 100 mL of 0.5 N HCl and 100 mL of 1 N NaHCO3
dried over MgSO4
concentrated
The residue was purified with a 40M Biotage column
来源 ID: ord-d303685f2cb944afb45e8d3181ca39cb