Reaktion #1504044

Reaktionsgleichung

Glycine

2-Benzyl-1,4-butanediol

sodium hydroxide

β-NAD+

glycine

anisaldehyde

sodium hydroxide

sodium hydroxide

sodium hydroxide

→

(R)-2-benzylbutyrolactone

Lösungsmittel

water

acetone

methylene chloride

ethanol

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.DISSOLUTIONAfter the enzyme has dissolved the pH
2. 2
   workup.STIRRINGthe reaction mixture is stirred at 30° C
3. 3
   SonstigeDuring the reaction
4. 4
   Temperaturheating)
5. 5
   Extraktionextracted 3 times with 250 ml of methylene chloride
6. 6
   Extraktionfollowed by continuous extraction with 1 liter of ethyl acetate for 24 hours
7. 7
   ExtraktionThe ethyl acetate extract
8. 8
   Trocknenis dried over anhydrous magnesium sulfate
9. 9
   Sonstigeevaporated under reduced pressure

Vorschrift

Glycine (18.8 grams) is dissolved in 2 liters of deionized water, and the pH is adjusted by the addition of 10% sodium hydroxide to 9.0. 2-Benzyl-1,4-butanediol (10.0 grams) is dissolved in 150 ml of acetone added to the glycine solution with stirring, followed by the addition of β-NAD+ (Sigma, 0.5 grams). To the resulting solution is added horse liver alcohol dehydrogenase (Sigma, 250 mg, approximately 400 units). After the enzyme has dissolved the pH is readjusted to 9.0 with 10% sodium hydroxide, and the reaction mixture is stirred at 30° C. During the reaction, the pH is maintained at 9.0 with a pH-stat by the addition of 10% sodium hydroxide. Progress of the reaction is monitored by thin layer chromatography (Silica gel plates, eluent methylene chloride; visualization by dipping in a solution of 5% anisaldehyde in ethanol and heating). When the reaction is complete as judged by thin layer chromatography, the reaction mixture is adjusted to a pH of 13 with 10 M sodium hydroxide and then extracted 3 times with 250 ml of methylene chloride. The pH of the aqueous mixture is then adjusted to 3 with concentrated HCl, followed by continuous extraction with 1 liter of ethyl acetate for 24 hours. The ethyl acetate extract is dried over anhydrous magnesium sulfate and evaporated under reduced pressure to yield (R)-2-benzylbutyrolactone as a yellowish solid.

Quelle