Influence of solvent on degree of acylation in the formation of sucrose esters

Abstract

Sucrose palmitates were prepared by the interesterification of sucrose and methyl palmitate in different solvents. The ratio of methyl palmitate to sucrose in dimethylformamide (DMF) solution was varied so that the effect on yield and ester composition could be evaluated. When sucrose esters were prepared in DMF, the palmitoyl groups approximated a random distribution when only penta- and lower esters were formed. When the proportion of palmitoyl groups was increased, hexa- through octaesters were formed, but the yield was less than that calculated for a random distribution. The interesterification of sucrose and methyl palmitate in solvents other than DMF, but under otherwise identical reaction conditions, yielded different reaction products. Only traces of sucrose esters were produced in hexamethylphosphoramide and formylmorpholine. Reactions in dimethylsulfoxide and N-methyl-2-pyrrolidinone yielded larger percentages of higher esters than were obtained in DMF. However the distribution was far from random.