Réaction #64051

Équation de réaction

2-butyryl-3-hydroxy-5-mesitylcyclohex-2-en-1-one

dichloromethyl methyl ether

→

2-butyryl-3-hydroxy-5-(3-formyl-2,4,6-trimethylphenyl)cyclohex-2-en-1-one

Rendement 26.7%

Solvants

dichloroethane

dichloroethane

Conditions de réaction

Traitement

1. 1
   workup.ADDITIONwas added dropwise over a 25 minute period
2. 2
   workup.ADDITIONAfter the addition
3. 3
   workup.STIRRINGthe mixture was stirred for 5 minutes at 0° C., for 30 minutes at room temperature and for 2 hours
4. 4
   Températureunder reflux
5. 5
   AutreThe cooled reaction mixture
6. 6
   workup.ADDITIONwas poured into a separatory funnel
7. 7
   workup.ADDITIONcontaining
8. 8
   Autrecrushed ice
9. 9
   workup.STIRRINGwas shaken thoroughly
10. 10
    AutreThe organic layer was separated
11. 11
    Extractionthe aqueous solution was extracted with methylene chloride
12. 12
    LavageThe combined organic solution was washed with water
13. 13
    Séchagedried over anhydrous sodium sulfate
14. 14
    Autreevaporated to dryness
15. 15
    Autreto give a crude brown oil (0.70 g)
16. 16
    AutrePurification by column chromatography over silica gel (eluant dichloromethane)

Mode opératoire

To a solution of 2-butyryl-3-hydroxy-5-mesitylcyclohex-2-en-1-one (1.20 g) in dichloroethane (20 ml) at 0° C. was added titanium tetrachloride (300 g) over a period of 3 minutes. While the solution was stirred and cooled dichloromethyl methyl ether (0.46 g) in dichloroethane(20 ml) was added dropwise over a 25 minute period. After the addition was complete, the mixture was stirred for 5 minutes at 0° C., for 30 minutes at room temperature and for 2 hours under reflux. The cooled reaction mixture was poured into a separatory funnel containing crushed ice and was shaken thoroughly. The organic layer was separated, and the aqueous solution was extracted with methylene chloride. The combined organic solution was washed with water, dried over anhydrous sodium sulfate and evaporated to dryness to give a crude brown oil (0.70 g). Purification by column chromatography over silica gel (eluant dichloromethane) gave 2-butyryl-3-hydroxy-5-(3-formyl-2,4,6-trimethylphenyl)cyclohex-2-en-1-one (0.35 g) as a pale yellow oil. Proton nuclear magnetic resonance spectrum (CDCl3 ; δ in ppm): 1.0 (3H, t); 1.68 (2H, m); 2.43 (3H, s); 2.48 (3H, s); 2.61 (3H, s); 2.65-4.20 (7H, m); 6.94 (1H, s); 10.54 (1H, s); 18.33 (1H, s).

Source