Reaktion #2299113

Reaktionsgleichung

1,1,4,4,6-pentamethyl-1,2,3,4-tetrahydronaphtalene

methyl 5-(chloromethyl)-2-furoate

aluminum trichloride

→

Methyl 5-[(3,5,5,8,8-pentamethyl-5,6,7,8-tetrahydro-2-naphthalenyl)methyl]-2-furoate

Ausbeute 46.0%

Lösungsmittel

methylene chloride

methylene chloride

—

ethyl acetate hexanes

Reaktionsbedingungen

Aufarbeitung

1. 1
   TemperaturThe solution is refluxed for an additional two hours
2. 2
   Sonstigethe unreacted aluminum trichloride is quenched with water over 15 minutes
3. 3
   ExtraktionThe crude product is extracted with methylene chloride
4. 4
   Wascheneluted with methylene chloride
5. 5
   SonstigeThe solvent is evaporated in vacuo to syrup
6. 6
   FiltrationThe crude product us purified with silica gel (300 g) via a plug filtration column
7. 7
   WaschenMethyl 5-[(3,5,5,8,8-pentamethyl-5,6,7,8-tetrahydro-2-naphthalenyl)methyl]-2-furoate 6 is eluted with 2% ethyl acetate/hexanes
8. 8
   Sonstigeto afford 15.4 g (46% yield)

Vorschrift

To a solution containing 1,1,4,4,6-pentamethyl-1,2,3,4-tetrahydronaphtalene 4 (20 g, 99 mmol) and methyl 5-(chloromethyl)-2-furoate 5 (17.28 g, 99 mmol) in methylene chloride (500 mL, 0.2 M), aluminum trichloride (16.46 g, 124 mmol) is added slowly as a solid at the reflux temperature of methylene chloride. The solution is refluxed for an additional two hours. The reaction is monitored by tlc in 10% ethyl acetate/hexanes solution. The reaction is cooled to room temperature and the unreacted aluminum trichloride is quenched with water over 15 minutes. The crude product is extracted with methylene chloride and passed through silica gel (80 g) and eluted with methylene chloride. The solvent is evaporated in vacuo to syrup. The crude product us purified with silica gel (300 g) via a plug filtration column. Methyl 5-[(3,5,5,8,8-pentamethyl-5,6,7,8-tetrahydro-2-naphthalenyl)methyl]-2-furoate 6 is eluted with 2% ethyl acetate/hexanes to afford 15.4 g (46% yield). NMR 1.25 (s, 6H), 1.28 (s, 6H), 1.67 (s, 4H), 2.23 (s, 3H), 3.89 (s, 3H), 3.97 (s, 2H), 5.95 (d, 1H), 7.09 (m, 3H).

Quelle