Dimethyl Sulfate → 5-Methoxy-4-methyl-3-decene

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

5.0 g of 4-methyl-3-decen-5-ol dissolved in 25 ml of toluene are added dropwise over a period of 30 minutes at 80° C. while stirring to 1.54 g of a 55-60% sodium hydride dispersion in 25 ml of toluene. The mixture is stirred at 80° C. for 12 hours, cooled to 40° C. and treated dropwise with 5.6 g of dimethyl sulphate, the temperature again rising to 80° C. In order to complete the reaction, the mixture is stirred at 80° C. for a further 3 hours. After cooling to 40° C., 10 ml of ethanol are added thereto. The mixture is heated to boiling for a short period and then treated with cold 2N sodium hydroxide. The product is taken up in hexane, washed neutral, chromatographed on 250 g of silica gel in order to remove the oil of the sodium hydride dispersion used and the thus-obtained crude product is fractionally distilled. There are obtained 4.1 g (76% of theory) of 5-methoxy-4 -methyl-3-decene of boiling point 100°-105° C./14 Torr, nD20 =1.4337. Odour: very fresh, fruity, green, apple-like, blueberries, blackberries, herbaceous.

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