Carbonate Couplers and Functional Cyclic Carbonates from Amino Acids and Glucosamine

On the basis of glycerol carbonate, four coupling reagents 3a‐d were prepared. Their synthesis and characterisation, starting from glycerol carbonate 2, is described. To evaluate the differences in reactivity these couplers were reacted with valine methyl ester and the results were compared with the already known coupler 3a. Reaction conditions influenced the conversion of the couplers 3a‐d containing phenyl, 4‐nitrophenyl, imidazolyl and acetone oxime leaving groups; highest conversion and fastest reaction rates were obtained with 3b. The coupling reagents 3a and b were used for the synthesis of functional carbonate building blocks from amino acid methyl esters and glucosamine. magnified image