Selective synthesis of aliphatic ethylene glycol sulfonate surfactants

Abstract

The selective synthesis of a series of components in a commercial surfactant mixture was studied. The general structure of the surfactant was a glycerol-based double chain monosulfonate molecule, with a C8-Guerbert alcohol, 2-ethylhexanol, at C-1, a pentyloxy group at C-3 and a 3-oxypropane-1-sulfonic acid or an ethoxylated 3-oxypropane-1-sulfonic acid side chain at the C-2 position. The main chain alcohol was obtained by a base catalyzed reaction of 2-ethylhexyl glycidyl ether with a pentyl alcohol. High C-3 selectivity was obtained. Two methods were used for the construction of the ethoxylated side chain at the C-2. A sequence consisting of O-allylation followed by ozonolysis and sodium borohydride work-up gave good yields of the desired ethoxylated homologs. A shorter, more efficient method involved the reaction with 1,2-ethylene sulfate. This method gave the ethoxylated bomologs with high selectivity and in high yields. O-Propane sulfonation was accomplished by the reaction of the appropriate alkoxides with 1,3-propane sulfone. The pure sodium sulfonates were isolated in good overall yields by continuous extraction with hexane or diethyl ether. © Acta Chemica Scandinavica 1996.