反应详情

温度

-65 °C

(S)-N-methyl-1-phenyl-2-(1-piperidinyl)ethanamine (360.0 mg, 1.65 mmol) was dissolved in ether (12 mL) and n-butyl lithium (2.5M in hexanes, 0.66 mL, 1.65 mmol) was added to the solution at -65° C. The solution was stirred for 5 min at -65° C., warmed to 0° C. and stirred for 10 min at 0° C. To a second flask was added CuI (262 mg, 1.38 mmol) and 10 mL of diethyl ether. This solution was cooled to -40° C. and treated with n-butyl lithium (0.55 mL, 1.38 mmol). The solution in the first flask was cooled to -35° C. and added via canula to the solution of n-BuCu in the second flask. The resulting solution was stirred for 15 min at -35° C., for 10 min at -30° C., and cooled to -78° C. After 5 min, chlorotrimethylsilane (0.437 mL, 3.44 mmol) was added and stirred for 15 min. 2-Cyclopentenone (112.8 mg, 1.38 mmol) was added slowly at -78° C. to the reaction mixture, which was quenched after 1 hr by adding 4N NH4Cl (15 mL) at -78° C. and extracted with ether (20 mL). The extract was washed with 1N HCl (15 mL), dried (Na2SO4) and concentrated. The oily residue was purified by column chromatography on silica gel (5:1=pentane/ether) to afford (S)-3-n-butylcyclopentanone (98.7 mg, 51% chemical yield, 44% ee, [α]D =-54.4 (c=3.00, benzene)).

1. temperaturewarmed to 0° C.
2. stirringstirred for 10 min at 0° C
3. temperatureThis solution was cooled to -40° C.
4. temperatureThe solution in the first flask was cooled to -35° C.
5. additionadded via canula to the solution of n-BuCu in the second flask
6. stirringThe resulting solution was stirred for 15 min at -35° C., for 10 min at -30° C.
7. temperaturecooled to -78° C
8. waitAfter 5 min
9. stirringstirred for 15 min
10. customwas quenched after 1 hr
11. additionby adding 4N NH4Cl (15 mL) at -78° C.
12. extractionextracted with ether (20 mL)
13. washThe extract was washed with 1N HCl (15 mL)
14. dry with materialdried (Na2SO4)
15. concentrationconcentrated
16. customThe oily residue was purified by column chromatography on silica gel (5:1=pentane/ether)