Reaction #2328972

Reaction equation

ammonium chloride

potassium-t-butoxide

methoxymethyltriphenylphosphonium chloride

methyl 4-oxocyclohexanecarboxylate

→

methyl 4-methoxymethylidenecyclohexanecarboxylate

Yield 87.3%

Solvents

water

tetrahydrofuran

THF

Conditions

Workup

1. 1
   workup.ADDITIONthe resulting solution added dropwise at −10 to 4° C. over 80 minutes
2. 2
   workup.STIRRINGAfter stirring at 0 to 4° C. for 60 minutes
3. 3
   workup.DISTILLATIONThe solvent of the reaction mixture was distilled off under reduced pressure and 600 mL of hexane
4. 4
   workup.ADDITIONwas added
5. 5
   workup.STIRRINGby stirring at room temperature for 30 minutes
6. 6
   FiltrationThe precipitate was filtrated
7. 7
   Washwashed again with 600 mL of hexane
8. 8
   Washthe mixture was washed in turn with a mixed solution of methanol-water (1:1), water, and saturated solution
9. 9
   DryingAfter dried over anhydrous sodium sulfate
10. 10
    workup.DISTILLATIONthe solvent was distilled off under reduced pressure

Procedure

263.4 g of methoxymethyltriphenylphosphonium chloride was dispersed in 750 mL of tetrahydrofuran (THF) and 86.2 g of potassium-t-butoxide were added at −9 to −4° C. over 5 minutes. After stirring at −4 to −11° C. for 30 minutes, 100.0 g of methyl 4-oxocyclohexanecarboxylate was dissolved in 300 mL of THF and the resulting solution added dropwise at −10 to 4° C. over 80 minutes. After stirring at 0 to 4° C. for 60 minutes, 7.0 g of ammonium chloride and 20 mL of water were added. The solvent of the reaction mixture was distilled off under reduced pressure and 600 mL of hexane was added, followed by stirring at room temperature for 30 minutes. The precipitate was filtrated and the precipitate was suspended and washed again with 600 mL of hexane. After combining with the hexane filtrate, the mixture was washed in turn with a mixed solution of methanol-water (1:1), water, and saturated solution. After dried over anhydrous sodium sulfate, the solvent was distilled off under reduced pressure to obtain 103 g of methyl 4-methoxymethylidenecyclohexanecarboxylate as an oily substance.

Source