反应详情

32 g of 4,6,6-trimethyl-1,3-cyclohexadiene-1-carbaldehyde [prepared according to A. F. Thomas et al., Helv. Chim. Acta, 59 (1976), p. 2261-7] in 80 ml of THF were added dropwise to a Grignard compound which had been prepared beforehand from 6 g of magnesium turnings and 32 g of 1-bromo-1-propene in 120 ml of THF. The temperature was maintained at 20° with a water bath during the addition, after which the mixture was heated and kept at reflux over 30 minutes. The reaction mixture was poured into an ice/water ixture and then extracted with ether. The organic phase was washed to neutrality, dried and concentrated. The crude product was then oxidized with 210 g of activated manganese dioxyde (see Houben Weyl, Vol. 7, 1, page 178, 1951; E. M. Goldman, Org. Chem., 34, 1979, 1969) in 200 ml of petroleum ether.

1. temperatureThe temperature was maintained at 20° with a water bath during the addition
2. temperatureafter which the mixture was heated
3. temperatureat reflux over 30 minutes
4. extractionextracted with ether
5. washThe organic phase was washed to neutrality
6. customdried
7. concentrationconcentrated