Propanal → HCID 87410178, compound

Participants

Reaction Steps

Anhydrous MgCl2 (27.0 g, 284 mmol) was charged into a 1 liter, 4-necked round bottom flask, and ethyl acetate (150 ml) was added. The suspension was stirred at room temperature, and a solution of TiCl3(OiPr) (34% in ethyl acetate; 21.50 g, 34.3 mmol) was added dropwise over 1.5 hour. The reaction mixture was stirred overnight at room temperature, and after that heated to 70° C. 6-Methyl 2-heptanone (110.0 g, 858 mmol) was added over 2.5 hours, followed by a slow addition of propanal (105.0 g, 1716 mmol) over 6 hours. Stirring at 70° C. was continued for 22 hours. After cooling at room temperature, the black reaction mixture was poured onto a mixture of ice (100 g), water (300 ml) and 25% aqueous H3PO4 (100 ml). The aqueous phase was discarded and the organic phase washed with 25% aq. potassium citrate, then twice with 10% aqueous K2CO3 and twice with brine. Drying over Na2SO4 and evaporation of the solvent afforded the crude product. Fractional distillation though a Vigreux column followed by a second distillation through a Fischer column afforded the desired ketone (32.0 g, 22.2% yield).

Provenance & Evidence