The reaction of the dianion of β-enaminoketones with electrophiles. Part 6. Synthesis of γ′- and ε-nitro-β-enaminoketones.

Abstract

α′- And γ-dianions of acyclic β-(monoalkylamino)-α,β-unsaturated ketones can attack the double bond of nitroalkenes affording γ′- and ε-nitro-β-enaminoketones in good to high yields. In contrast to the corresponding 1,3-dicarbonyl dianions, cyclic products from intramolecular Henry reactions are never observed. Quenching the reaction with sulphuric acid ε-nitro-β-enaminoketones are converted in low yields into dihydropyrroles.