CARO'S ACID-SILICA GEL: AN EFFICIENT AND VERSATILE CATALYST FOR THE ONE-POT SYNTHESIS OF TETRAHYDROBENZO[b]PYRAN DERIVATIVES

An efficient one-pot synthesis of tetrahydrobenzo[b]pyran is described. This involved the three-component reaction of aromatic aldehydes, molononitrile, and dimedone in the presence of a catalytic amount of Caro's acid supported on silica gel in ethanol/water under reflux.