Synthesis of stereoregular head,tail hydroxylated nylons derived from D-glucose

A simple procedure for the preparation of stereoregular polyhydroxypolyamides, i.e., head,tail hydroxylated nylons, derived from D-glucaric acid and alkylenediamines is described. Sodium D-glucarate 6,3-lactone was made in two steps from monopotassium D-glucarate by way of D-glucaro-6,3-lactone. Methanol insoluble salt of sodium 6-[N-(aminoalkyl)]-D-glucaramide monomer precursors were conveniently prepared by refluxing methanol solutions of even-numbered C-2 to C-12 aliphatic diamines with insoluble sodium D-glucarate-6,3-lactone. Each of the resulting salts was esterified/lactonized at the C-1 carboxylate terminus with HCl/methanol, and the products were made basic to give the corresponding free base amino acid ester/lactone mixture. The latter spontaneously underwent self-polymerization to give the target polyamides. An important feature of this general procedure for stereoregular polyamides from chiral D-glucaric acid is that it does not require any carbohydrate hydroxyl group protection/deprotection steps.