Michael Reaction of Conjugated Nitro Olefins with Carboxylic Acid Dianions and with Ester Enolates: New Synthesis of γ-Keto Acids and γ-Keto Esters

Article abstract of DOI:10.1021/jo00190a003

Base-sensitive conjugated nitro olefins 2 reacted with lithium dianions of carboxylic acids 3 or with lithium enolates of esters 4 at a low temperature of ca. -100 deg C, and subsequent treatment of the Michael adducts with aqueous acid yielded γ-keto acids 5 or esters 5' in a one-pot operation, respectively.Results of both the reactions have been compared.Some applications of the resulting γ-keto esters in organic synthesis have also been demonstrated in lactone synthesis and cyclenone annulation.