Reaktion #65579

Reaktionsgleichung

3-cyclododecylpropanoic acid

KBr

1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride

tetronic acid

triethylamine

dimethylaminopyridine

→

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

Lösungsmittel

hexane ethyl acetate

dimethylformamide

Reaktionsbedingungen

Aufarbeitung

1. 1
   SonstigeAfter 10 minutes the ice bath is removed
2. 2
   workup.STIRRINGto stir overnight at room temperature
3. 3
   workup.ADDITIONThe reaction mixture is then poured into 1.0N hydrochloric acid
4. 4
   Extraktionextracted 3 times with ethyl acetate
5. 5
   Waschenwashed with brine
6. 6
   Trocknendried over magnesuim sulfate
7. 7
   Filtrationfiltered
8. 8
   Einengenconcentrated
9. 9
   Sonstigeto give a yellow oil
10. 10
    Sonstigeto give an off white solid

Vorschrift

To a solution of 0.70 g (7 mmol) of tetronic acid in 20 ml of dry dimethylformamide at 0° C. is added 1.1 ml (836 mg, 8.3 mmol) of triethylamine and 0.31 g (2.5 mmol) of dimethylaminopyridine. After stirring for 5 minutes, 2.0 g (8.3 mmol) of 3-cyclododecylpropanoic acid is added followed by 1.6 g (8.3 mmol) of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride. After 10 minutes the ice bath is removed and the reaction mixture is allowed to stir overnight at room temperature. The reaction mixture is then poured into 1.0N hydrochloric acid and extracted 3 times with ethyl acetate. The organic layers are combined, washed with brine, dried over magnesuim sulfate, filtered and concentrated to give a yellow oil. The oil is subjected to flash chromatography using acidic silica gel and hexane/ethyl acetate (3:2) as the mobile phase to give an off white solid: m.p. 99°-102° C.; IR (KBr) 2940, 1710, 1600 and 1470 cm-1 ; NMR (CDCl3) (mixture of tautomeric forms) δ 1.34 (mc, 22H), 1.50 (bs, 1H), 1.61 (m, 2H), 2.92 (m, 2H), 4.55 and 4.70 (s, 2H); MS (EI)

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