反应详情

温度

-40 °C

Methyllithium (170 mL of a 1.6 M solution with Et2O, 260 mmol) was added to a stirring mixture of copper (I) iodide (25 g, 130 mmol) and Et2O (130 mL), at −40° C. under a nitrogen atmosphere. After stirring for 10 min at −40° C., ethyl 2-methyl-4-oxo-2-cyclohexene-1-carboxylate (12 g, 66 mmol) was added. After stirring for 30 min at −40° C., the reaction mixture was allowed to warm to −20° C. After stirring for 90 min at −20° C., saturated aqueous ammonium chloride and EtOAc were added sequentially, the mixture was partitioned between more saturated aqueous ammonium chloride and EtOAc, the layers were separated, the organic material washed sequentially with saturated aqueous ammonium chloride (2×) and brine, dried (Na2SO4), filtered, and the filtrate was concentrated. The residue was dissolved with DCM, silica gel (39 g) was added to the solution, and the volatiles were removed under reduced pressure. The residue was subjected to flash chromatography on silica gel (gradient elution; 19:1 to 9:1 hexane-EtOAc) to give ethyl 2,2-dimethyl-4-oxocyclohexanecarboxylate (8.9 g, 68% yield; racemic mixture) as a clear yellow oil.

1. stirringAfter stirring for 30 min at −40° C.
2. temperatureto warm to −20° C
3. stirringAfter stirring for 90 min at −20° C.
4. customthe mixture was partitioned between more saturated aqueous ammonium chloride and EtOAc
5. customthe layers were separated
6. washthe organic material washed sequentially with saturated aqueous ammonium chloride (2×) and brine
7. dry with materialdried (Na2SO4)
8. filtrationfiltered
9. concentrationthe filtrate was concentrated
10. dissolutionThe residue was dissolved with DCM, silica gel (39 g)
11. additionwas added to the solution
12. customthe volatiles were removed under reduced pressure