Reaktion #5798

Reaktionsgleichung

isopropanol

Potassium cyanide

(R*,R*)-α-2-propenyloxiraneethanol

water

→

(±)-cis-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 dimethoxymethane
7. 7
   workup.ADDITIONcamphorsulfonic acid is added
8. 8
   workup.STIRRINGthe solution is stirred for 18 hours at room temperature
9. 9
   EinengenConcentration and flash chromatography
10. 10
    Einengenafter concentration in vacuo

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 dimethoxymethane, camphorsulfonic acid is added, and the solution is stirred for 18 hours at room temperature. Concentration and flash chromatography after concentration in vacuo provides 1.20 g of (±)-cis-6-(2-propenyl)-1,3-dioxane-4-acetonitrile.

Quelle