EFFICIENT SYNTHESES FOR ACETYLSTARCHES

Acetylation of high-amylose starch to products of high average degree of substitution (DS) with yield of >90% proceeds in 1-2 h using potass ium carbonate as activating agent. Acetylstarches of DS <2 are availab le by acetylation with stoichiometric amounts of acetic anhydride in N -methyl-2-pyrrolidone applying organic catalysts as 4-dimethylaminopyr idine and 1,4-diazabicyclo[2.2.2]octane, respectively. Reaction times of 1 h and less are sufficient to receive the desired acetates in high yield.