Zinc carbenoid-mediated chain extension of β-keto amides

The reaction of β-keto amides with ethyl(iodomethyl)zinc provides access to a wide variety of γ-keto amides, including primary, secondary, and tertiary amides. Although the reaction of α-substituted β-keto amides are in many cases unsatisfactory, the method can be applied to a broad spectrum of substrates that possess imide and olefinic functionality.