Reaktion #216718

Reaktionsgleichung

1-(3-dimethylaminopropyl)-3-ethyl carbodiimide hydrochloride

KBr

tetronic acid

dimethylaminopyridine

3-cyclohexylpropanoic acid

→

3-(3-cyclohexyl-1-oxopropyl)-4-hydroxy-2(5H)-furanone

Lösungsmittel

N,N-dimethylformamide

triethylamine

Reaktionsbedingungen

Aufarbeitung

1. 1
   SonstigeAfter 10 minutes the ice bath is removed
2. 2
   workup.STIRRINGto stir overnight
3. 3
   SonstigeThe reaction mixture is quenched with 1N hydrochloric acid
4. 4
   Waschenthe solution is washed 3 times with hexanes
5. 5
   Waschenwashed with brine
6. 6
   Trocknendried over magnesium sulfate
7. 7
   Sonstigeevaporated
8. 8
   Sonstigeto give a yellow solid, which
9. 9
   Sonstigeis recrystallized from hexanes
10. 10
    Sonstigeto give light yellow crystals

Vorschrift

To a solution of 2.0 g of tetronic acid in 40 ml of dry N,N-dimethylformamide was added (at 0° C.) 3.1 ml of triethylamine and 0.81 g of dimethylaminopyridine. After stirring for 5 minutes, 3.4 ml of 3-cyclohexylpropanoic acid was added, followed by 4.6 g of 1-(3-dimethylaminopropyl)-3-ethyl carbodiimide hydrochloride. After 10 minutes the ice bath is removed and the mixture is allowed to stir overnight. The reaction mixture is quenched with 1N hydrochloric acid and the solution is washed 3 times with hexanes. The combined organic layers are combined, washed with brine, dried over magnesium sulfate and evaporated to give a yellow solid, which is recrystallized from hexanes to give light yellow crystals: m.p. 75°-78° C.; IR (KBr) 2910, 2820, 1750, 1640, 1600 cm-1 ; NMR (CDCl3) δ 0.9-1.8 (1 1H, m), 2.9 (t, 2H, J=6 Hz), 4.7 and 4.5 (s, 2H (tautomers)); MS EI M+ 238.

Quelle