反应详情

A solution of 4-methoxy-6-trifluoromethylpyran-2-one (10 g, 52 mmol) in a methanolic magnesium methanolate solution (8.5% Mg(OMe)2, 62.8 g, 61 mmol) was heated under reflux for 2 hours. Concentrated aqueous HCl (25.5 g, 250 mmol) was added to the reaction solution, and the mixture was heated under reflux for a further 2 hours, then cooled and concentrated in vacuo to about 20% of the initial volume. The residue was mixed with 10 mL each of methylene chloride and water. The organic phase was separated off, washed with water, dried over sodium sulfate and concentrated. Kugelrohr distillation at 0.04 mbar and about 160° C. afforded methyl 6,6,6-trifluoro-3,5-dioxohexanoate (2.8 g, 13 mmol, 26%) as a pale yellow oil.

1. temperatureunder reflux for 2 hours
2. temperaturethe mixture was heated
3. temperatureunder reflux for a further 2 hours
4. temperaturecooled
5. concentrationconcentrated in vacuo to about 20% of the initial volume
6. additionThe residue was mixed with 10 mL each of methylene chloride and water
7. customThe organic phase was separated off
8. washwashed with water
9. dry with materialdried over sodium sulfate
10. concentrationconcentrated
11. distillationKugelrohr distillation at 0.04 mbar and about 160° C.