Cyclodextrins in reactions of alcohols with aqueous hypochlorite: catalysts or reactants?

Abstract

β-Cyclodextrin, a cyclic oligosaccharide/poly alcohol, reacts with aqueous sodium hypochlorite at elevated temperatures, resulting in a drop in the pH of the medium. Hypochlorite-induced oxidations of 1-phenyl-1-propanol or benzyl alcohol in the presence of the cyclic oligosaccharide are enhanced by lowering of pH rather than by inverse phase transfer catalysis. The secondary alcohol is inert in aqueous hypochlorite maintained at high pH, even in presence of the cyclodextrin. More rapid and efficient oxidations may be effected by pH control than by heating and/or addition of β-cyclodextrin.