We examine how the ~(13)C shifts of oligomers of branching polyesters made from glycerol or erythritol and the difunctional carboxylic acids malonic acid, succininc acid or glutaric acid reflect the location of the ester links on the alcohols, and whether these are influenced by a reaction of the acids at their second site. Assignments were made by observing the new shifts that appeared as the oligomers formed in reactions whose initial conditions were chosen to simplify the products; symmetry of structure was also used. Substitution parameters for each acid were obtained for each carbon in the alcohols, and found to be sensitive to whether the second function of the malonic and succinic acids had participated in ester formation. Cyclic products were discovered early in transesterification reactions of dimethyl malonate. For a fractal polyester a nomenclature is provided, an example prepared and characterized, and then shown to be modified by reactions: Fractal(G,S[-O-H]), fringed with hydroxyl groups, gave an acid-fringed fractal: Fractal(G,S[-CO-O-H]) (a hyperbranch of glycerol and succinate residues).
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