Alternating Stereoregular Head, Tail–Tail, Head‐Poly(Alkylene d‐Glucaramides) Derived from a Homologous Series of Symmetrical Diamido‐di‐d‐Glucaric Acid Monomers

Abstract

A method for the synthesis and purification of a homologous series of symmetrical diamido‐diacids derived from d‐glucaric acid and six alkylenediamines is described. Treating d‐glucaro‐6,3‐lactone with an equimolar amount of lithium acetate dihydrate yielded lithium d‐glucarate‐6,3‐lactone, which in turn was reacted with six alkylenediamines in dimethyl sulfoxide to give the target diamido‐diacids. Six new alternating stereoregular polyamides, head, tail–tail, head‐poly(alkylene d‐glucaramides), were then synthesized by simple polycondensation reactions between the activated diamido‐diacids [6,6′‐(N,N′‐alkylene)‐bis(d‐glucaramid‐1‐oic acid)s] and the alkylenediamines. Number average molecular weights for the polyamides were estimated by ¹H NMR end group analysis. Models for the three‐dimensional shape of these alternating stereoregular polymers were produced from a combination of ¹H NMR data, molecular modeling studies performed on d‐glucaramide, and crystal structures of various acyclic d‐glucaric acid derivatives.

Keywords:

• Stereoregular
• Poly(alkylene‐d‐glucaramide
• Alternating
• Diamido‐diacids

Acknowledgment

This work was supported partially by a Graduate Assistance in Areas of National Need (GAANN) fellowship to S. Styron and a USDA CRESS grant to the University of Montana.