Sc(OTf)3-catalyzed cyclocondensation of 2-propylresorcinol with diethoxymethane. Formation and fragmentation of resorcin[n]arenes

The cyclocondensation of an equimolar amount of 2-propylresorcinol with diethoxymethane in the presence of Sc(OTf)3 in acetonitrile produced a mixture of resorcin[n]arenes (n=4–7) with a kinetically controlled product distribution. However, the reaction with an excess amount of diethoxymethane produced the thermodynamically favored resorcin[4]arene as the major product. The fragmentation/recombination mechanism of the resorcin[n]arenes was discussed.