反应详情

温度

-78 °C

A stirred solution of 4 g of 3,5-di-tert-butyl-4-hydroxyacetophenone in 250 ml of dry methylene chloride is cooled to -78° C. and 7.3 ml di-iso-propyl ethylamine (i-Pr2EtN) is added followed by 8.1 ml of trimethylsilyl trifluoromethanesulphonate (TMSOTf). The mixture is stirred at -78° C. for 10 minutes and is allowed to warm to ambient temperature over 1 hour. The mixture is cooled again to -78° C., and 3.6 ml of dicyclopropylketone is added followed by 32 ml of 1M titanum tetrachloride solution in methylene chloride. After stirring for 1 hr, the mixture is washed with 1N aqueous hydrochloric acid and the solvents are removed under reduced pressure. The residue is dissolved in 50 ml of methanol-1N aqueous hydrochloric acid and stirred for 1 hr at room temperature. The mixture is concentrated under reduced pressure and partitioned between methylene chloride and water. The organic phase is washed with aqueous sodium bicarbonate, brine and dried over sodium sulphate. The solvents are evaporated and the residue is purified by flash chromatography (10% ethyl acetate in hexane), and the product is recrystallized from hexane to give 1-(3,5-di-tert-butyl-4-hydroxyphenyl-3,3-dicyclopropylprop-2-en-1-one as an orange solid.

1. temperatureto warm to ambient temperature over 1 hour
2. temperatureThe mixture is cooled again to -78° C.
3. stirringAfter stirring for 1 hr
4. washthe mixture is washed with 1N aqueous hydrochloric acid
5. customthe solvents are removed under reduced pressure
6. dissolutionThe residue is dissolved in 50 ml of methanol-1N aqueous hydrochloric acid
7. stirringstirred for 1 hr at room temperature
8. concentrationThe mixture is concentrated under reduced pressure
9. custompartitioned between methylene chloride and water
10. washThe organic phase is washed with aqueous sodium bicarbonate, brine
11. dry with materialdried over sodium sulphate
12. customThe solvents are evaporated
13. customthe residue is purified by flash chromatography (10% ethyl acetate in hexane)
14. customthe product is recrystallized from hexane