Asymmetric Aldol Reaction of Pyruvate Promoted by Chiral Tertiary Amines

The direct asymmetric aldol reaction of alpha-ketoesters catalyzed by chiral tertiary amines is reported. The described methodology is characterized by mild reaction conditions and distinct product selectivity determined by the starting materials. In the developed transformation pyruvates undergo highly selective self-condensation reaction, whereas cross-aldol reaction take place predominantly for their carbon chain homologues in presence of aldehyde acceptors. Notably, addition of bulky phenol moiety into pyruvate inhibit the spontaneous lactonization of products and enhance the enantioselectivity.