反应详情

温度

100 °C

5-Benzyloxy-2-hydroxybenzaldehyde (2.01 g, 8.80 mmol) is dissolved in 30 ml of DMF and treated successively with potassium carbonate (1.22 g, 8.80 mmol) and tert-butyl acrylate (1.22 g, 13.2 mmol). The mixture is heated at 100° C. for 1 hour. The temperature is gradually raised to 135° C. over a period of 2 hours, and held at 135° C. for 1 hour. The resultant dark mixture is cooled and evaporated to remove most of DMF. The residue is partitioned between ether and water, and the aqueous phase is discarded. The organic layer is dried (MgSO4), evaporated and purified by silica gel chromatography (6% ethyl acetate/hexane) to give tert-butyl 6-benzyloxy-2H-1-benzopyran-3-carboxylate as a yellow crystalline solid, m.p. 64°-67° C.

1. temperatureThe temperature is gradually raised to 135° C. over a period of 2 hours
2. temperatureThe resultant dark mixture is cooled
3. customevaporated
4. customto remove most of DMF
5. customThe residue is partitioned between ether and water
6. dry with materialThe organic layer is dried (MgSO4)
7. customevaporated
8. custompurified by silica gel chromatography (6% ethyl acetate/hexane)