Reacción #157447

Ecuación de reacción

4,4-dimethyl cyclohexanone

n-BuLi

methoxymethyl triphenylphosphonium chloride

→

(4,4-dimethyl cyclohexylidene)methyl methyl ether

Disolventes

THF

—

hexanes

THF

ammonium chloride

ethyl acetate

Condiciones de reacción

Tratamiento posterior

1. 1
   Temperaturacooled to −78° C.
2. 2
   TemperaturaAfter 1 hr at −78° C. the mixture was slowly warmed to 0° C.
3. 3
   workup.STIRRINGstirred at room temperature for 48 hr
4. 4
   OtroLayers were separated
5. 5
   Extracciónthe aqueous phase was extracted with ethyl acetate
6. 6
   LavadoCombined organics were washed with brine
7. 7
   Secadodried over Na2SO4
8. 8
   Filtraciónfiltered
9. 9
   Concentraciónconcentrated in vacuo
10. 10
    OtroThe residue was triturated with hexanes, solids
11. 11
    Otrowere removed by filtration
12. 12
    Concentraciónthe filtrated was concentrated in vacuo
13. 13
    workup.DISSOLUTIONThe residue was dissolved in dichloromethane (40 mL)
14. 14
    workup.ADDITIONPS-TsNHNH2 (8 g; ca. 3.7 mmol/g) and acetic acid (2 drops) were added
15. 15
    workup.STIRRINGthe mixture was stirred at room temperature for 24 hr
16. 16
    OtroResin was removed by filtration
17. 17
    Lavadowashed (CH2Cl2, MeOH, CH2Cl2)
18. 18
    ConcentraciónCombined filtrate/washings were concentrated in vacuo

Procedimiento

To a mixture of methoxymethyl triphenylphosphonium chloride (35.5 g, 0.104 mol) in THF (400 mL) at 0° C. was added n-BuLi (33.1 mL of a 2.8M solution in hexanes; 0.095 mol). The mixture was stirred at 0° C. for 30 min., cooled to −78° C. and a solution of 4,4-dimethyl cyclohexanone (10.0 g, 0.079 mol) in THF (100 mL) was added, dropwise. After 1 hr at −78° C. the mixture was slowly warmed to 0° C., diluted with satd ammonium chloride (400 mL) and ethyl acetate (100 mL) and stirred at room temperature for 48 hr. Layers were separated and the aqueous phase was extracted with ethyl acetate. Combined organics were washed with brine, dried over Na2SO4, filtered and concentrated in vacuo. The residue was triturated with hexanes, solids were removed by filtration and the filtrated was concentrated in vacuo. The residue was dissolved in dichloromethane (40 mL), PS-TsNHNH2 (8 g; ca. 3.7 mmol/g) and acetic acid (2 drops) were added and the mixture was stirred at room temperature for 24 hr. Resin was removed by filtration and washed (CH2Cl2, MeOH, CH2Cl2). Combined filtrate/washings were concentrated in vacuo, affording (4,4-dimethyl cyclohexylidene)methyl methyl ether as an oil.

Fuente