Condensation and Polycondensation of Terephthaldehyde with MethylD-Hexopyranosides

Abstract

The condensation and polycondensations of terephthaldehyde (1) and methyl D‐hexopyranosides (gluco‐, galacto‐ and mannopyranoside) are described. Methyl α‐D‐glucopyranoside and methyl α‐D‐galactopyranoside react with 1 to give mono‐5 a and 6 a and diacetals 5 b and 6 b. Their structures were confirmed by NMR and IR spectroscopy. The polycondensation of methyl α‐D‐mannopyranoside (4) with 1 was studied in various solvents within the temperature range of 80–140°C. Regardless of the conversion or the initial comonomer feed ratios the composition of polycondensates depended on the reaction conditions leading to the formation of materials with diverse solubilities, molecular weights and optical properties. The regioselective polycondensation of 1 and 4 was examined by the 1H NMR spectroscopy of polymer 7. In the case of five‐membered cyclic acetal units, mixtures of the endo‐H and exo‐H dioxolan‐2‐yl system diastereomers are formed. Experimental examples of functionalization via ester units in polymer molecules 8 are described and the efficiency of the reaction routes and procedures are evaluated. The molecular weight was estimated by size‐exclusion chromatography (SEC) measurements before and after the functionalization.

Synthesis and Characterization of Complex Mixtures Consisting of Cyclic and Linear Polyamides from EthylBis-Ketal Galactarates

“…A similar strategy was employed by Prömpers et al to achieve a synthesis of polyurethanes with pendant hydroxyl groups (37). Recently, Munoz-Guerra et al elected to block the hydroxyl groups on galactaric acid with acetal groups to produce carbohydrate-based polyesters (38) Maślińska-Solich et al investigated the properties of polymers formed in the acetalization of methyl D-hexopyranosides with dialdehydes (39,40). Condensation with terephtalaldehyde initially led to low molecular weight linear polycondensates which branched and crosslinked at high conversions.…”

Chiral Polymers Containing a Carbohydrate Moiety: Synthesis

“…9-12) were 4:1. Further characterization of this polymer using 13 Figure 1). As can be seen in the inset of spectrum B in Figure 1, there are more alkoxy carbons present than in the corresponding inset of spectrum C. Since -CH 2 Br groups in polymer can be hydrolyzed to hydroxyl groups during the course of the reaction, it is reasonable to assume that Table 2.…”

“…[13] The polycondensation of methyl a-Dmannopyranoside (1) with terephthaldehyde under selected reaction conditions gave polymers with molecular weights up to 10 000 g Á mol À1 . The X-ray structure of diacetal with a 16-membered macrocyclic loop, obtained as a product of the condensation of (1) and 1,4-bis(2-formylphenoxy)-butane (7), has been presented together with polymeric compounds resulting from the polycondensation.…”

The solvent dynamics at pore surfaces in molecular gels studied by field-cycling magnetic resonance relaxometry

“…2 Experimental section 2.1 Materials and gel preparation 4,6,4 0 ,6 0 -O-terephthalylidene-bis(methyl a-D-glucopyranoside), gelator 1, was synthesized according to the procedure described previously. 29 Ethylene glycol (EG) and 1,3-propanediol (PG) for gel preparation were provided by Sigma-Aldrich and used without further purication. The gels were prepared from mixtures of powdered gelator 1 and a suitable solvent under different weight concentrations of the gelator ranging from 0.5 to 4 wt% via a thermal heating-cooling cycle, which allows the formation of the noncovalent interactions responsible for the gel network.…”