A concise method for the synthesis of 2-tetralone by titanium tetrachloride-promoted cyclization of 4-aryl-2-hydroxybutanal diethyl acetal

4-Aryl-2-hydroxybutanal diethyl acetal, prepared from the reaction of benzyl Grignard reagent and glycidaldehyde diethyl acetal, was treated with titanium tetrachloride to give 2-tetralone in good yield. This highly efficient transformation involves tandem oxonium formation, intramolecular Friedel–Crafts alkylation, deethoxylation, and tautomerization in the same flask.