Diethyl Ether → 3-(1,3-Butadien-1-yl)-2,4,4-trimethyl-2-cyclohexen-1-one

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Reaction Steps

A solution of 70 g of crude 3-oxo-β-ionol and 1.5 g of paratoluenesulphonic acid in 300 ml of toluene is stirred at reflux temperature for 40 minutes with simultaneous removal of the water formed by means of a water separator. The cooled mixture is treated with 300 ml of ether, the organic phase is washed three times with soda solution and three times with water, dried and concentrated. There are obtained 61 g of crude product which contains more than 90% of 2,4,4-trimethyl-3-(buta-1,3-diethyl)cyclohex-2-en-1-one according to gas-chromatographical analysis. Distillation of the crude product over a 15 cm column gives 45 g of olfactorily-good 2,4,4-trimethyl-3-(buta-1,3-dienyl)cyclohex-2-en-1-one of boiling point 74°-75° C./0.06 mm Hg.

Provenance & Evidence