Catalyzed Addition of Aldehydes to Activated Double Bonds—A New Synthetic Approach

Abstract In the presence of cyanide ions as catalyst, aromatic and heterocyclic aldehydes can be smoothly added to α,β‐unsaturated ketones, esters, and nitriles in aprotic solvents to form γ‐diketones, 4‐oxo carboxylic esters, and 4‐oxo nitriles. Thiazolium salts in the presence of bases are also suitable catalysts; they permit not only addition of aromatic and heterocyclic aldehydes but also the addition of aliphatic aldehydes.