反应详情

1 g of 4-dimethylaminopyridine and 30.3 g (0.1 mole) of 4-cyano-4-heptyl-4'-hydroxybicyclohexane (obtainable from 4-(1,4-dioxaspiro[4,5]dec-8-yl)-cyclohexanone by introduction of the nitrile group with tosylmethyl isocyanide (TOSMIC), alkylation with LDA (diisopropylamine/butyl-lithium) and heptyl bromide, detachment of the keto-protective group, reduction of the ketone with NaBH4 to the alcohol and separation of the isomers) are added to 19.8 g (0.1 mole) of trans-4-pentylcyclohexanecarboxylic acid in 75 ml of CH2Cl2, with stirring. A solution of 27.7 g (0.105 mole) of dicyclo-hexylcarbodiimide in 50 ml of methylene chloride is added dropwise at 0°, while controlling the temperature, and the mixture is then stirred at room temperature for a further hour. The urea precipitated is separated off and the methylene chloride phase is washed with dilute HCl and saturated NaHCO3 solution and dried. The product is then purified by filtration over a short silica gel column and by crystallisation. 4-Cyano-4-heptyl-4'-(trans-4-pentylcyclohexylcarbonyloxy)-bicyclohexane is obtained.

1. stirringthe mixture is then stirred at room temperature for a further hour
2. customThe urea precipitated
3. customis separated off
4. washthe methylene chloride phase is washed with dilute HCl and saturated NaHCO3 solution
5. customdried
6. filtrationThe product is then purified by filtration over a short silica gel column and by crystallisation