Réaction #332116

Équation de réaction

isobutyryl chloride

lithiumdiisopropylamine

ethyl 2-(4-hexylphenyl)acetate

→

desired product

Rendement 70.5%

ethyl 2-(4-hexylphenyl)-4-methyl-3-oxopentanoate

Rendement 70.5%

Solvants

hexane tetrahydrofuran

tetrahydrofuran

Conditions de réaction

Traitement

1. 1
   Températurethe solution was warmed to 0° C.
2. 2
   TempératureThe reactuion solution was cooled to −60° C. again
3. 3
   AutreThe reaction was quenched with saturated aqueous sodium hydrogen carbonate (150 ml)
4. 4
   Extractionthe reaction solution was extracted with ethyl acetate
5. 5
   SéchageThe organic layer was dried over anhydrous magnesium sulfate
6. 6
   Filtrationfiltered
7. 7
   Concentrationthe filtrate was concentrated under reduced pressure
8. 8
   AutreThe resulting residue was purified by silica gel column chromatography

Mode opératoire

6.0 g (24 mmol) of ethyl 2-(4-hexylphenyl)acetate was dissolved in 130 mL of dry tetrahydrofuran under a nitrogen atmosphere and cooled to −60° C. After addition of 31.8 mL (36.2 mmol) of 1.14 M solution of lithiumdiisopropylamine in hexane/tetrahydrofuran, the solution was warmed to 0° C. and stirred for 1 hours. The reactuion solution was cooled to −60° C. again and stirred with 3.6 g (34 mmol) of isobutyryl chloride at −60° C. to room temperature for 15 hours. The reaction was quenched with saturated aqueous sodium hydrogen carbonate (150 ml), and the reaction solution was extracted with ethyl acetate. The organic layer was dried over anhydrous magnesium sulfate and filtered, and the filtrate was concentrated under reduced pressure. The resulting residue was purified by silica gel column chromatography using ethyl acetate:hexane (0:100 to 1:9) as the eluent to give 5.39 g of the desired product as a pale yellw oil.

Source