Reaktion #413718

Reaktionsgleichung

Benzyl chloroformate

L-valinol

triethylamine

→

alcohol

Ausbeute 79.5%

N-Benzyloxycarbonyl-L-valinol

Ausbeute 79.5%

Lösungsmittel

chloroform

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturto warm to,room temperature over 2 h
2. 2
   SonstigeAfter the reaction mixture was evaporated
3. 3
   workup.ADDITIONethyl acetate (1500 ml) was added to the residue
4. 4
   Waschenthe organic solution was washed (1N NaOH, brine)
5. 5
   Trocknendried (MgSO4)
6. 6
   Sonstigeevaporated
7. 7
   SonstigeThe residue was purified by flash chromatography
8. 8
   Waschena stepwise gradient elution of ether:hexane (1:5)

Vorschrift

Benzyl chloroformate (91.0 g, 95% purity) was added dropwise over a period of 1 h to a precooled (0° C.) solution of L-valinol (50.0 g) and triethylamine (60.0 g) in chloroform (1500 ml). The reaction mixture was stirred for 1 h at 0° C. and then allowed to warm to,room temperature over 2 h. After the reaction mixture was evaporated, ethyl acetate (1500 ml) was added to the residue and the organic solution was washed (1N NaOH, brine), dried (MgSO4), and evaporated. The residue was purified by flash chromatography, using a stepwise gradient elution of ether:hexane (1:5) followed by ether, to give the alcohol (91.4 g) as a white waxy solid; TLC, Rf =0.23, hexane:ethanol (50:50).

Quelle