As a convenient synthetic method of γ-keto acids, oxoalkylation of carboxylic acids with nitroolefins was examined. Carboxylic acid dianions reacted with conjugated nitroolefins at low temperature (−100°C) and a variety of γ-keto acids were obtained on acidic workup in moderate to good yields.
Michael reaction of conjugated nitro olefins with carboxylic acid dianions and with ester enolates: new synthesis of .gamma.-keto acids and .gamma.-keto esters