反应详情

5,6-Dimethyl-4-hydroxy-2-oxo-2H-pyran (J. Chem. Soc. Perkin Trans 1, 1980, 2272) (10 g, 71 mmol) was dissolved in 66 mL of dioxan and 33 mL of 0.88 NH3 solution and the mixture refluxed for 3 h. The resulting suspension was then allowed to cool to room temperature overnight, filtered and the solid collected and dried in vacuo to provide the title compound as a white crystalline solid (6.5 g). The filtrate was concentrated to approximately 10 mL in vacuo, and a second crop of solid collected by filtration (1.0 g). Both crops were combined and used in the next synthetic step.

1. filtrationfiltered
2. customthe solid collected
3. customdried in vacuo