An asymmetric Michael addition of α,α-disubstituted aldehydes to maleimides leading to a one-pot enantioselective synthesis of lactones catalyzed by amino acids.

A cheap and fast construction of both enantiomers of substituted succinimides is reported. α- or β-amino acids, such as β-phenylalanine and α-tert-butyl aspartate, were found to be efficient organocatalysts for the reaction between α,α-disubstituted aldehydes and maleimides. Products containing contiguous quaternary-tertiary stereogenic centers are obtained in high to quantitative yields and excellent selectivities utilizing low catalyst loadings (0.5-3.5%). Finally, a one-pot efficient asymmetric synthesis of lactones is described.