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 C2 to C12 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.