Decarboxylative Claisen Condensations with Substituted Malonic Acid Half Oxyesters

Abstract A decarboxylative Claisen condensation involving substituted malonic acid half oxyesters (SMAHOs) as pronucleophiles has been developed. The addition of their magnesium enolates to various acyl donors allows the synthesis of functionalized α-substituted β-keto esters in moderate to excellent yields (13–96%). In addition to acyl chlorides and acid anhydrides, these conditions proved efficient for the use of carboxylic acids as acylating agents, thus allowing to greatly extend the scope of this transformation (32 examples overall).