反应详情

To a nitrogen-flushed, 150 mL steel reaction vessel with teflon-coated magnetic stirbar was added 30.0 g methyl 3-buteneoate (300 mmol, 1 eq.). Hexafluoroacetone (55.8 g, 336 mmol, 1.1 eq.) was condensed into the vessel at −78° C. The reaction vessel was sealed under 1 atmosphere of nitrogen and warmed to room temperature slowly. The reaction was heated at 160° C. for 16 hours after which the pressure had decreased dramatically. The vessel was cooled in an ice bath and the excess hexafluoroacetone was carefully vented through a saturated potassium hydroxide solution. The crude reaction mixture was vacuum distilled using a 6-inch, vacuum-jacketed vigereaux column with a short-path distillation head. The product was isolated at 75-80° C. (6 Torr) as a colorless liquid. A second distillation of the prefraction resulted in a total isolated yield of 55.4 g (69%) of E-methyl 6,6,6-trifluoro-5-hydroxy-5-(trifluoromethyl)hex-2-enoate (I).

1. customTo a nitrogen-flushed
2. custom150 mL steel reaction vessel with teflon-coated magnetic stirbar
3. customcondensed into the vessel at −78° C
4. customThe reaction vessel was sealed under 1 atmosphere of nitrogen
5. temperatureThe reaction was heated at 160° C. for 16 hours after which the pressure
6. temperatureThe vessel was cooled in an ice bath
7. customThe crude reaction mixture
8. distillationdistilled
9. customThe product was isolated at 75-80° C. (6 Torr) as a colorless liquid
10. distillationA second distillation of the prefraction
11. customresulted in