Reaktion #91078

Reaktionsgleichung

2-(2-oxocyclopentyl)acetic acid

H2SO4

ethanol

→

title compound

Ethyl 2-(2-Oxocyclopentyl)acetate

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturunder reflux overnight
2. 2
   EinengenThe reaction mixture was concentrated
3. 3
   workup.ADDITIONthe liquid residue was added into ice-water (200 mL)
4. 4
   ExtraktionThe aqueous mixture was extracted with DCM (3×200 mL)
5. 5
   WaschenThe combined organic layers were washed with H2O (300 mL), brine (300 mL)
6. 6
   Trocknendried over Na2SO4
7. 7
   Sonstigedecanted
8. 8
   Einengenconcentrated
9. 9
   Sonstigedried under vacuum

Vorschrift

To a solution of 2-(2-oxocyclopentyl)acetic acid (23.6 g, 166 mmol) in absolute ethanol (400 mL) was added H2SO4 (16.28 g, 166 mmol). The resultant solution was heated under reflux overnight. The reaction mixture was concentrated and the liquid residue was added into ice-water (200 mL). The aqueous mixture was extracted with DCM (3×200 mL). The combined organic layers were washed with H2O (300 mL), brine (300 mL), dried over Na2SO4, decanted, concentrated and dried under vacuum to afford the title compound as a light yellow liquid (27.2 g). LCMS m/z=171.3 [M+H]+; 1H NMR (400 MHz, CDCl3) δ ppm 1.19 (t, J=7.14 Hz, 3 H), 1.50-1.62 (m, 1 H), 1.65-1.80 (m, 1 H), 1.92-2.02 (m, 1 H), 2.12 (dd, J=16.7, 8.86 Hz, 1 H), 2.19-2.29 (m, 2 H), 2.30-2.44 (m, 2 H), 2.65 (dd, J=15.12, 2.6 Hz, 1H), 4.07 (q, J=7.14 Hz, 2H).

Quelle