2-Oxobutanoic Acid → 2-Isovaleramidobut-2-enoic acid
Reaktionsgleichung
O=[C:2]([CH2:6][CH3:7])[C:3]([OH:5])=[O:4].[C:8]([NH2:14])(=[O:13])[CH2:9][CH:10]([CH3:12])[CH3:11].O>C1(C)C=CC=CC=1>[C:8]([NH:14]/[C:2](=[CH:6]\[CH3:7])/[C:3]([OH:5])=[O:4])(=[O:13])[CH2:9][CH:10]([CH3:12])[CH3:11]Komponenten
5
Edukt 3
Produkt 1
Reagenzien, Katalysatoren, Lösungsmittel 1
Versuchsvorschrift
A solution of 1.07 g (10.5 mmole) of 2-keto-butyric acid and 0.71 g (7.0 mmole) of isovaleramide in 15 ml of toluene was stirred under reflux with collection of H2O in a small Dean-Stark trap. After 5 hrs, the solution was cooled, resulting in fairly heavy crystallization. After standing, the solid was collected on a filter and washed with toluene and then with CH2Cl2. Yield of white crystals=0.47 g, mp 172°-174° (slight prelim. softening). The material was recrystallized from diisopropyl ketone. Tlc (4:1 toluene-AcOH) now showed only a faint trace of the other isomer. Yield of white crystals=0.32 g (25%), mp 175° (slight prelim. softening). NMR indicated essentially exclusively Z-isomer.