反应详情

2-(Trimethylsilyloxy)buta-1,3-diene (40 g, 281 mmol) was weighed into a Teflon™ microwave container. Isobutyl methacrylate (50.8 mL, 317 mmol) was added followed by 4,4′-methylenebis(2,6-di-tert-butylphenol) (0.5 g, 1.177 mmol), finally 1-butyl-3-methylimidazolium hexafluorophosphate (0.5 mL) was added, the vessel transferred to the Advancer microwave and heated for 4 hr (normal absorption, no fixed hold time, 190° C.). After 1 hr 20 min an error message was seen for the temperature probe, the error was cleared and heating was continued for a further hour. At this time the software had frozen forcing a shutdown at the mains. The reaction mixture was allowed to cool to RT. Tetrahydrofuran (THF) (200 mL) was added and the solution transferred to a round bottomed flask. 2M HCl was added and the reaction mixture left to stir overnight. DCM was added to the reaction mixture, whereupon an emulsion formed. An attempt to filter this was unsuccessful, and the mixture was left to stand overnight. The organic layer was separated, dried (Na2SO4) and evaporated to give a sticky oil. Flash column chromatography, eluting with ethyl acetate/isohexane gave 2-methylpropyl 1-methyl-4-oxocyclohexanecarboxylate as a yellow oil (12.74 g, 60.0 mmol, 21.35% yield).

1. additionwas added
2. temperatureheated for 4 hr (
3. customnormal absorption
4. customno fixed hold time, 190° C.
5. temperatureheating
6. waitwas continued for a further hour
7. temperatureAt this time the software had frozen
8. additionTetrahydrofuran (THF) (200 mL) was added
9. customthe solution transferred to a round bottomed flask
10. addition2M HCl was added
11. waitthe reaction mixture left
12. additionDCM was added to the reaction mixture, whereupon an emulsion
13. customformed
14. filtrationAn attempt to filter this was unsuccessful, and the mixture
15. waitwas left
16. waitto stand overnight
17. customThe organic layer was separated
18. dry with materialdried (Na2SO4)
19. customevaporated
20. customto give a sticky oil
21. washFlash column chromatography, eluting with ethyl acetate/isohexane