Potassium Cyanide → (+/-)-cis-2,2-Dimethyl-6-(2-propenyl)-1,3-dioxane-4-acetonitrile
Reaktionsgleichung
[C-:1]#[N:2].[K+].[CH2:4]([C@@H:7]([OH:12])[CH2:8][C@@H:9]1[CH2:11][O:10]1)[CH:5]=[CH2:6].[CH:13](O)([CH3:15])[CH3:14].O>>[CH3:14][C:13]1([CH3:15])[O:10][C@@H:9]([CH2:11][C:1]#[N:2])[CH2:8][C@@H:7]([CH2:4][CH:5]=[CH2:6])[O:12]1Komponenten
4
Versuchsvorschrift
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 2x 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.