Abstract
The authors developed a highly efficient and versatile 6′-OH cinchona alkaloid catalyzed conjugate addition of carbonyl donors to α,β-unsaturated aldehydes to synthesize chiral aldehydes with excellent yields and enantioselectivities. A wide range of carbonyl donors (α-substituted-β-keto esters in the presence of bifunctional organocatalyst A or α-cyano esters in the presence of B) and α,β-unsaturated aldehydes can be used to form tetrasubstituted stereocenters. This new methodology was successfully applied to the catalytic enantioselective total synthesis of (+)-tanikolide.