反応 #502079

反応方程式

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

溶媒

Tetrahydrofuran

tetrahydrofuran

反応条件

後処理

1. 1
   その他fitted with condenser
2. 2
   温度The flask was cooled to <10° C.
3. 3
   温度whilst maintaining a temperature of <10° C
4. 4
   workup.STIRRINGas stirred for 2 hours at <10° C
5. 5
   温度cooling
6. 6
   その他The crude reaction mixture
7. 7
   抽出was extracted into methyltert-butyl ether (2×300 mL)
8. 8
   洗浄the organic phase washed with water (200 mL)
9. 9
   乾燥The organic phase was dried over magnesium sulphate
10. 10
    ろ過filtered
11. 11
    その他the solvent removed by evaporation

実験手順

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.

出典