Reaktion #3082

Reaktionsgleichung

(-)-8-chloro-6-hydroxy-octanoic acid

pyridine

thionyl chloride

→

(+)-6,8Dichloro-octanoic acid

Lösungsmittel

toluene

Reaktionsbedingungen

Aufarbeitung

1. 1
   TemperaturThe mixture was then refluxed for 1 hour
2. 2
   SonstigeThe organic phase was then removed
3. 3
   Waschenwashed with 20 ml of water
4. 4
   SonstigeThe aqueous phase was then removed
5. 5
   Extraktionextracted twice with 20 ml of diethylether
6. 6
   TrocknenThe combined ether extracts were dried over magnesium sulfate
7. 7
   SonstigeAfter that, the solvent was evaporated under vacuum

Vorschrift

To a solution of 3.0 g (15.4 mmoles) of (-)-8-chloro-6-hydroxy-octanoic acid (-)-(VI) and 0.06 g (0.8 mmoles) of pyridine in 40 ml toluene, 4.1 g (34.4 mmoles) of thionyl chloride were added slowly. The mixture was then refluxed for 1 hour, cooled to room temperature and added to 60 ml of ice water. The organic phase was then removed, washed with 20 ml of water and stirred for 4 hours with 35 ml of 2N NaOH. The aqueous phase was then removed, adjusted to a pH of 1 with 3N HCl and extracted twice with 20 ml of diethylether. The combined ether extracts were dried over magnesium sulfate. After that, the solvent was evaporated under vacuum. (+)-6,8Dichloro-octanoic acid (+)-(VII) was obtained in a yield of 2.6 g (80% of the theoretical yield). [α]D20 =+30.5° (c=1; benzene).

Quelle