反应详情

The starting material is prepared as follows: 5-Phenoxysalicylaldehyde (6.17 g, 28.8 mmol) is dissolved in 100 ml of 1,4-dioxane and treated with potassium carbonate (7.96 g, 57.6 mmol) and methyl vinyl ketone (3.03 g, 43.2 mmol) under nitrogen. The mixture is heated at reflux for 3 hours. Water is added and three extractions with dichloromethane are carried out. The organic extracts are combined, dried (MgSO4) and evaporated. Purification by flash chromatography (silica gel, 15% EtOAc/hexane) yields 3-acetyl-6-phenoxy-2H-1-benzopyran as a solid.

1. customThe starting material is prepared
2. temperatureThe mixture is heated
3. temperatureat reflux for 3 hours
4. extractionthree extractions with dichloromethane
5. dry with materialdried (MgSO4)
6. customevaporated
7. customPurification by flash chromatography (silica gel, 15% EtOAc/hexane)