SnCl4 or TiCl4: highly efficient catalysts for the detetrahydropyranylation and demethoxymethylation of phenolic ethers and sequential one-pot asymmetric synthesis of 3-aryl-2-hydroxy-2,3-dihydroindan-1-ones from chalcone epoxides

SnCl4 or TiCl4 catalysts provided a rapid and efficient detetrahydropyranylation and demethoxymethylation of phenolic ethers and a sequential one-pot intramolecular Friedel-Crafts alkylation of chalcone epoxides under mild reaction conditions. The reaction took 2-3 min to give the phenols and 1-indanones in an excellent yield (90-98%) at 0 degrees C without affecting other functional groups. With these catalysts, our protocol gave regioselective products as trans-3-aryl-2-hydroxy-1-indanones in an excellent yield (76-98%) and an enantiomeric excess of up to 99.9% under the same conditions.