SELECTIVE SYNTHESIS OF ALIPHATIC ETHYLENE-GLYCOL SULFONATE SURFACTANTS

The selective synthesis of a series of components in a commercial surf actant mixture was studied. The general structure of the surfactant wa s a glycerol-based double chain monosulfonate molecule, with a C-8-Gue rbert alcohol, 2-ethylhexanol, at C-l, 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 obtai ned by a base catalyzed reaction of 2-ethylhexyl glycidyl ether with a pentyl alcohol. High C-3 selectivity was obtained. Two methods were u sed for the construction of the ethoxylated side chain at the C-2. A s equence consisting of O-allylation followed by ozonolysis and sodium b orohydride work-up gave good yields of the desired ethoxylated homolog s. A shorter, more efficient method involved the reaction with 1,2-eth ylene sulfate. This method gave the ethoxylated homologs with high sel ectivity and in high yields. O-Propane sulfonation was accomplished by the reaction of the appropriate alkoxides with 1,3-propane sulfone. T he pure sodium sulfonates were isolated in good overall yields by cont inuous extraction with hexane or diethyl ether.