Reaktion #53537

Reaktionsgleichung

Et2O

ester

2,2,3-trimethylbutanoic acid ethyl ester

LAH

→

2,2,3-trimethyl-butanol 2,2,3-trimethyl-butanol

Lösungsmittel

ethylbenzene

Reaktionsbedingungen

Aufarbeitung

1. 1
   SonstigeA 500 mL round-bottom-flask equipped with a stir bar
2. 2
   Sonstigewas flushed with Ar
3. 3
   workup.ADDITIONcharged with 50 mL dry THF
4. 4
   Temperaturdid not reflux (required 50 min)
5. 5
   workup.WAITat ambient temperature for 14 h
6. 6
   TemperaturThe reaction solution was re-cooled to 0° C.
7. 7
   Sonstigecarefully quenched by addition of EtOAc
8. 8
   workup.ADDITION1 N NaOH was added until a granular precipitate
9. 9
   Sonstigeformed (7.5 mL)
10. 10
    FiltrationThe mixture was filtered on a pad of diatomaceous earth which
11. 11
    Waschenwas then washed 3×100 mL Et2O
12. 12
    Trocknendried over Na2SO4
13. 13
    SonstigeThe solution was decanted
14. 14
    Einengenconcentrated in vacuo

Vorschrift

A 500 mL round-bottom-flask equipped with a stir bar was flushed with Ar and charged with 50 mL dry THF and a 1 M solution of LAH in Et2O (87.5 mL, 87.5 mmol, 0.625 equiv). The solution was cooled to 0° C. with an ice bath and the above ethyl ester (22.1 g, 140 mmol, 1.0 equiv) (approximately a 50% solution in ethylbenzene) was added dropwise at such a rate that the solution did not reflux (required 50 min). After addition of the ester, the reaction was stirred at 0° C. for 2 h and then at ambient temperature for 14 h. The reaction solution was re-cooled to 0° C. and carefully quenched by addition of EtOAc. 1 N NaOH was added until a granular precipitate formed (7.5 mL). The mixture was filtered on a pad of diatomaceous earth which was then washed 3×100 mL Et2O. The organics were combined and dried over Na2SO4. The solution was decanted and concentrated in vacuo to yield 2,2,3-trimethyl-butanol 2,2,3-trimethyl-butanol as a nearly colorless oil (11.7 g of alcohol in 15.4 g of a mix with ethylbenzene). The crude product was used without further purification.

Quelle