Regioselective Ring‐Opening of Oxetanes Catalyzed by Lewis Superacid Al(C6F5)3

This study details an aluminum‐catalyzed regioselective isomerization of 2,2‐disubstituted oxetanes to yield homoallylic alcohols. The reaction takes place in toluene at 40 °C, employing 1 mol % of Al(C6F5)3 as catalyst. This catalytic system shows a wide substrate scope (12 examples). The optimized conditions are especially useful for electron‐rich aryl oxetanes, completely suppressing the formation of allyl isomers and reducing the amount of the dimer by‐product. The synthetic applicability of the reported methodology is demonstrated by the enantioselective formal synthesis of curcuquinone and the σ1 receptor agonist RC‐33.