Co-melting of solid sucrose and multivalent cation soaps for solvent-free synthesis of sucrose esters

Sucrose fatty acid esters, useful as mild surfactants, have been synthesised in good yields in a solvent-free medium. High contents of monoesters and low saponification rate have been observed. The co-melting of sucrose and a multivalent cation soap such as magnesium or zinc soaps, under basic conditions, allowed the formation of a homogeneous reaction mixture, where solid sucrose was fully dissolved. The kinetic monitoring profiles are similar to reactions in homogeneous solutions, with fast initial formation of monoesters. As a consequence, conversion of sucrose in sucrose esters occurred in good yields. The specificity of multivalent cation soaps compared to monovalent cation soaps, for example, potassium stearate, was pointed out.