反应详情

A solution of ethyl 2-chromanecarboxylate (1.575 g, 7.68 mmol) in a mixture of tetrahydrofuran (75 ml) and water (2 ml) was added with sodium borohydride (0.686 g, 18.2 mmol) in small portions and the mixture was left under stirring at room temperature for 48 h. Afterwards the mixture was cooled at -10° C. and added with acetone (47 ml) stirring at room temperature for 0.5 h. Subsequently water (100 ml) was added and the mixture was extracted with dichloromethane. The combined organic phases were dried and the solvent was removed by evaporation under reduced pressure, thereby obtaining 1.218 g of the title product (97% yield).

1. waitthe mixture was left
2. temperatureAfterwards the mixture was cooled at -10° C.
3. stirringstirring at room temperature for 0.5 h
4. extractionthe mixture was extracted with dichloromethane
5. customThe combined organic phases were dried
6. customthe solvent was removed by evaporation under reduced pressure