Reaktion #502079

Reaktionsgleichung

Ethyl acetate

Aluminium chloride

lithium aluminium hydride

2-methyl-2-(4-methylpentyl)-1,3-dioxolane

lithium aluminium hydride

→

desired product

2-[(1,5-dimethylhexyl)oxy]ethanol

Lösungsmittel

Tetrahydrofuran

tetrahydrofuran

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigefitted with condenser
2. 2
   TemperaturThe flask was cooled to <10° C.
3. 3
   Temperaturwhilst maintaining a temperature of <10° C
4. 4
   workup.STIRRINGas stirred for 2 hours at <10° C
5. 5
   Temperaturcooling
6. 6
   SonstigeThe crude reaction mixture
7. 7
   Extraktionwas extracted into methyltert-butyl ether (2×300 mL)
8. 8
   Waschenthe organic phase washed with water (200 mL)
9. 9
   TrocknenThe organic phase was dried over magnesium sulphate
10. 10
    Filtrationfiltered
11. 11
    Sonstigethe solvent removed by evaporation

Vorschrift

Tetrahydrofuran (600 mL) was charged to 2 L flask fitted with condenser, nitrogen, thermocouple and mechanical stirrer. The flask was cooled to <10° C. and the flask was inerted with dry nitrogen fed a slow rate. Aluminium chloride (112 g, 840 mmol) was slowly added to the reaction flask whilst maintaining a temperature of <10° C. Then lithium aluminium hydride powder (15.9 g, 420 mmol) was added slowly over 30 minutes. The reaction mixture was stirred for a further 30 minutes at <10° C. To the reaction flask was added slowly a solution of 2-methyl-2-(4-methylpentyl)-1,3-dioxolane (72 g, 420 mmol) in tetrahydrofuran (50 mL) over 30 minutes. The reaction mixtures as stirred for 2 hours at <10° C. Ethyl acetate (200 g) was then added slowly to the reaction mixture to neutralise the excess lithium aluminium hydride—cooling was necessary to counteract the large exotherm. The crude reaction mixture was extracted into methyltert-butyl ether (2×300 mL) and the organic phase washed with water (200 mL). The organic phase was dried over magnesium sulphate, filtered and the solvent removed by evaporation to yield the desired product suitable for the next synthetic step as a colourless oil (100% pure by GC rpa, 70 g, 400 mmol, 96% chemical yield). A small sample was Kugelrohr distilled to give material suitable for olfactive analysis.

Quelle