反应详情

温度

0 °C

A solution of TosMIC (0.98 g, 4.98 mmol, 2.3 eq) in THF (3 mL) is poured, over 20 minutes, into a solution of potassium tert-butoxide (1.22 g; 10.9 mmol; 5 eq) in THF (7.5 mL) stirred at 0° C. under nitrogen. Then 200 μL of methanol are added to the mixture and stirring is maintained for 30 minutes at 0° C. In parallel, 3,4-dimethoxybicyclo[4.2.0]octa-1,3,5-trien-7-one (0.39 g, 2.17 mmol, 1 eq), lithium bromide (0.19 g, 2.17 mmol, 1 eq) and THF (2.5 mL) are transferred into a second three-necked flask. After cooling to 0° C. under nitrogen, the solution of TosMIC and potassium tert-butoxide is transferred to the reaction mixture. After returning to ambient temperature, the solution is heated to 40° C. and stirred for 16 hours at that temperature. The mixture is then hydrolysed with a solution of 11N HCl (0.7 mL, 7.73 mmol) in water (2 mL). After evaporating off the THF under reduced pressure, the product is extracted with 5 mL of dichloromethane. The organic phase is washed twice with 2×5 mL of water before being dried. The crude product is purified by column chromatography over silica gel using the binary mixture methylcyclohexane/ethyl acetate 75/25 to obtain the title product in the form of a cream-coloured powder.

1. stirringstirring
2. temperatureis maintained for 30 minutes at 0° C
3. temperatureAfter cooling to 0° C. under nitrogen
4. customAfter returning to ambient temperature
5. temperaturethe solution is heated to 40° C.
6. stirringstirred for 16 hours at that temperature
7. customAfter evaporating off the THF under reduced pressure
8. extractionthe product is extracted with 5 mL of dichloromethane
9. washThe organic phase is washed twice with 2×5 mL of water
10. custombefore being dried
11. customThe crude product is purified by column chromatography over silica gel using the binary mixture methylcyclohexane/ethyl acetate 75/25