Water → Benzyl 9-oxo-3-azaspiro(5.5)undec-7-ene-3-carboxylate

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Reaction Steps

Methyl vinyl ketone (1.64 ml), ethanol (5 ml) and water (5 ml) were added to benzyl 4-formylpiperidine-1-carboxylate (5 g). The mixture was then added to a boiling solution of potassium hydroxide (0.22 g) in ethanol (10 ml) and the resulting reaction mixture was refluxed for 1 h (TLC control). When the reaction was complete, the mixture was added to water (25 ml) and extracted with ethyl acetate (2×50 ml). The combined organic phases were dried (Na2SO4) and concentrated in vacuo. The crude product obtained in this way was purified by column chromatography (silica gel, 25% ethyl acetate/hexane). Yield: 2.8 g (46%)

Provenance & Evidence