Ammonium Chloride → 4-(2,6,6-Trimethyl-2-cyclohexen-1-ylidene)-butan-2-ol

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Reaction Steps

The resulting crude acetoxy compound of formula II (108 g) is dissolved in 400 ml of ethanol (96%) and added dropwise within 10 minutes at 20°-30° C with slight cooling to a suspension of 20 g of sodium borohydride in 600 ml of 96% ethanol. The mixture is then heated until a slight reflux occurs and stirred at this temperature for 15 minutes. The end of the reaction can be detected by a spontaneous colour change from dark-yellow to lemon-yellow. After cooling to room temperature, the cloudy mixture is poured on to saturated ammonium chloride solution/ice and the mixture is extracted with hexane. After the usual washing to neutrality with water and drying over anhydrous sodium sulphate, the solvent is evaporated under a vacuum. There are obtained 96 g of crude 4-(2,6,6-trimethyl-2-cyclohexen-1-ylidene)-butan-2-ol (formula III).

Provenance & Evidence