2-Cyclohexen-1-one, 5-methyl- → (S,S)-3-n-butyl-5-methylcyclohexanone

温度

-65 °C

(S)-N-methyl-1-phenyl-2-(1-piperidinyl)ethanamine (345.0 mg, 1.58 mmol) was dissolved in ether (12 mL) and n-butyllithium (2.5M in hexanes, 0.63 mL, 1.575 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 (251 mg, 1.32 mmol) and 10 mL of diethyl ether. This solution was cooled to -40° C. and treated with n-butyl lithium (0.53 mL, 1.323 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 30 min, 5-methyl-2-cyclohexenone (290 mg, 2.64 mmol) was added slowly at -78° C. The reaction mixture 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 (ether/pentane=1/8 followed by ether/pentane=1/5) to afford (S,S)-3-n-butyl-5-methylcyclohexanone (176 mg, 79% chemical yield, 39% ee, [α]D =5.5 (c=1.00, benzene)) and (R)-5-methyl-2-cyclohexenone (78 mg, 54% chemical yield, 28% ee, [α]D =22.8 (c=4.00, acetone)).

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 30 min
9. customThe reaction mixture was quenched after 1 hr
10. additionby adding 4N NH4Cl (15 mL) at -78° C.
11. extractionextracted with ether (20 mL)
12. washThe extract was washed with 1N HCl (15 mL)
13. dry with materialdried (Na2SO4)
14. concentrationconcentrated
15. customThe oily residue was purified by column chromatography on silica gel (ether/pentane=1/8 followed by ether/pentane=1/5)

ORDレコード

ord-fb5a9cce764540d6ba0ab18af1e01255

出典データセット

uspto-grants-1992_07

DOI

10.6084/m9.figshare.5104873.v1

特許番号

US05134238