Diastereoselective Synthesis of 4-Hydroxytetralones via a Cascade Stetter−Aldol Reaction Catalyzed by <i>N</i>-Heterocyclic Carbenes

A cascade Stetter−aldol reaction of phthalaldehyde and Michael acceptors catalyzed by N-heterocyclic carbenes was developed. The corresponding 3-substituted-4-hydroxytetralones were obtained in moderate to good yields with good trans-selectivities. On the contrary, the separated Stetter reaction followed by aldol reaction gave 3-substituted-4-hydroxytetralones with good cis-selectivity. Oxidation or dehydration of the resulted 4-hydroxytetralone gave the corresponding naphthalenediol or naphthol derivative, respectively, in good yield.