Reaktion #5782

Reaktionsgleichung

Potassium cyanide

(R*,R*)-α-2-propenyloxiraneethanol

isopropanol water

→

(±)-cis-2,2-dimethyl-6-(2-propenyl)-1,3-dioxane-4-acetonitrile

Reaktionsbedingungen

Aufarbeitung

1. 1
   Einengenconcentrated
2. 2
   Sonstigepartitioned between ethyl acetate and brine
3. 3
   ExtraktionThe aqueous layer is extracted 2× with ethyl acetate
4. 4
   Waschenthe combined ethyl acetate extracts are washed with brine
5. 5
   Trocknendried (magnesium sulfate)
6. 6
   workup.DISSOLUTIONThe crude product is dissolved in 20 mL of 2,2-dimethoxypropane
7. 7
   workup.ADDITIONcamphorsulfonic acid is added
8. 8
   workup.STIRRINGthe solution stirred for 18 hours at room temperature
9. 9
   EinengenConcentration and flash chromatography

Vorschrift

Potassium cyanide, 1.3 g (20 mmol), is added to a room temperature solution of (R*,R*)-α-2-propenyloxiraneethanol, 2.56 g (20 mmol), in 25 mL of 4:1 isopropanol-water. The solution is stirred for 20 hours at ambient temperature, concentrated, and partitioned between ethyl acetate and brine. The aqueous layer is extracted 2× with ethyl acetate and the combined ethyl acetate extracts are washed with brine and dried (magnesium sulfate). The crude product is dissolved in 20 mL of 2,2-dimethoxypropane, camphorsulfonic acid is added and the solution stirred for 18 hours at room temperature. Concentration and flash chromatography provides 1.30 g of (±)-cis-2,2-dimethyl-6-(2-propenyl)-1,3-dioxane-4-acetonitrile.

Quelle