Ethyl Acetoacetate → HCID 54370579, compound

Participants

Reaction Conditions

Reaction Steps

To a chilled suspension (0° C., ice-water bath) of sodium hydride (120 mg, 60% suspension in mineral oil, 3 mmol) in dry tetrahydrofuran (2 mL) under an inert atmosphere was added ethyl acetoacetate (330 μL, 2.6 mmol) in 4 equal portions over a period of 10 minutes. The homogeneous clear solution was stirred at 0° C. for 30 minutes followed by the dropwise addition of 2.5 M n-BuLi hexane solution (1.15 mL, 2.9 mmol) over 15 minutes. The orange dianion solution was stirred at 0° C. for an additional hour. The ice-water bath was replaced by an acetone-dry ice bath at -78° C. and the dianion solution was transferred via a cannula into a tetrahydrofuran (10 mL) solution containing 4-cyano-5,5-bis(4-fluorophenyl)-2,4-pentadienal (0.5 g, 1.7 mmol). The reaction mixture was allowed to stir at -78° C. for 5 minutes then was diluted with 40 mL of 1 M HCl aqueous solution. The organic material was extracted twice with ethyl acetate (50 mL×2). The organic layers were combined, dried over MgSO4 and concentrated under reduced pressure. The desired product was partitioned over a silica gel column and eluted with 1.5 liters of 30% (v/v) ethyl acetate in hexanes to give 0.57 g (79%) of the title compound as a gummy solid.

Provenance & Evidence