One-pot synthesis of γ-diketones, γ-keto esters, and conjugated cyclopentenones from nitroalkanes

Conjugated addition of primary nitroalkanes to alpha,beta-unsaturated ketones or alpha,beta-unsaturated esters, in the presence of two equivalents of DBU, allows the one-pot prepration of gamma-diketones or gamma-keto esters, respectively. When 2-aryl-1-nitroethane derivatives are employed as starting nitroalkanes in the reaction with alpha.beta-unsaturated ketones, the one-pot formation of cyclopentenones is observed.