反应详情

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).

1. additionadded dropwise within 10 minutes at 20°-30° C
2. temperatureThe mixture is then heated until
3. temperaturea slight reflux
4. customThe end of the reaction
5. extractionthe mixture is extracted with hexane
6. washAfter the usual washing to neutrality with water
7. dry with materialdrying over anhydrous sodium sulphate
8. customthe solvent is evaporated under a vacuum