反应详情

To 1.0 g (4.28 mmol) 4-oxo-piperidine-1-carboxylic acid benzyl ester in 5 mL anhydrous ether maintained between −25° C. and −30° C. were added, over 20 minutes, solutions of 0.7 mL (5.56 mmol) BF3Et2O in 1.5 mL anhydrous ether, followed by 0.67 mL (6.42 mmol) ethyl diazoacetate in 1.5 mL anhydrous ether, and the reaction was maintained between −25° C. and −30° C. for 1 hour. The mixture was allowed to warm up to room temperature, 10 mL 30% potassium carbonate solution was added and the mixture extracted with EtOAc (3×15 mL), the organic layers were combined and dried with MgSO4. After filtration and evaporation of the solvent the product was purified by flash column chromatography (silica, hexane/EtOAc 9:1 to 8:2).

1. additionwere added, over 20 minutes
2. temperaturethe reaction was maintained between −25° C. and −30° C. for 1 hour
3. extractionthe mixture extracted with EtOAc (3×15 mL)
4. dry with materialdried with MgSO4
5. filtrationAfter filtration and evaporation of the solvent the product
6. customwas purified by flash column chromatography (silica, hexane/EtOAc 9:1 to 8:2)