Metal triflate catalysed acetal exchange reactions of glycerol under solvent-free conditions

Abstract

Catalytic quantities of indium(III) triflate (In(OTf)3) efficiently promote transacetalisation reactions of glycerol with acyclic acetals to generate the corresponding cyclic acetals under solvent-free reaction conditions. The protocol is rapid and employs very mild reaction conditions. Unreactive ketones, such as acetophenone or benzophenone, undergo efficient acetalisation in the presence of In(OTf)3 and trimethyl orthoformate (TMOF) to give high conversions of the corresponding glycerol acetals.