Reaktion #10583

Reaktionsgleichung

1-cyclohexenecarboxylic acid

cyclohexane

ammonium sulphate

→

1,2,3,4,4a,5,6,7,8,9a-decahydro-9H-fluoren-9-one

Ausbeute 43.0%

Lösungsmittel

water

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturmaintaining a temperature of the reaction mass below 100° C
2. 2
   ExtraktionThe resulting mixture was then extracted 4 times with 300 ml of petroleum ether and 300 ml of diethyl ether
3. 3
   Waschenwashed successively with 5% aqueous ammonium hydroxide, brine
4. 4
   Trocknendried over magnesium sulphate
5. 5
   Einengenconcentrated in vacuum
6. 6
   workup.DISTILLATIONFractional distillation (b.p. 130° C. at 3.0 mmHg) of this crude product

Vorschrift

In a 250 ml three neck round bottom flask, equipped with a mechanical stirrer, a thermometer and a reflux condenser 16.276 g of polyphosphoric acid was charged and heated to a temperature of 70° C. 16.276 g of 1-cyclohexenecarboxylic acid and 10.592 g of cyclohexane were added dropwise maintaining a temperature of the reaction mass below 100° C. The mixture was stirred at 78° C. for additional 4.5 hours. The dark brown reaction mass was was poured onto 237 g of ice and neutralised with 89 g aqueous ammonium sulphate solution in 474 g of water. The resulting mixture was then extracted 4 times with 300 ml of petroleum ether and 300 ml of diethyl ether. All organic layers were combined, washed successively with 5% aqueous ammonium hydroxide, brine dried over magnesium sulphate and concentrated in vacuum. Fractional distillation (b.p. 130° C. at 3.0 mmHg) of this crude product yielded 10.294 g of 1,2,3,4,4a,5,6,7,8,9a-decahydro-9H-fluoren-9-one. 1H-NMR (CDCl3): δ 2.73 (q, J=7 Hz, 1 H), 2.2–0.5 (m, 17 H).

Quelle