Synthesis of New Homopolyester and Copolyesters by Anionic Ring‐opening Polymerization of α,α′,β‐Trisubstituted β‐Lactones

Abstract

Summary: Novel polyester and copolyesters have been prepared by anionic ring‐opening polymerization of racemic 4‐alkyloxycarbonyl‐3,3‐dimethyl‐2‐oxetanones that had been synthesized in five steps from diethyl oxalpropionate used as chemical precursor. The anionic polymerizations, realized in bulk or in solution with tetraethylammonium benzoate as initiator, led to a homopolymer and copolymers with high molecular weights and polydispersity indices close to unity. These features can be explained by the presence of two methyl groups on the same carbon atom in the lactone, preventing transfer reactions to the monomer. Preparation of seeds and re‐initiation by addition of fresh monomer confirmed a living process. The hydrolysis of poly[(R,S)‐3,3‐dimethylmalic acid] under physiological conditions yielded (R,S)‐3,3‐dimethylmalic acid. A terpolymer was also prepared for biological studies related to its use as biodegradable materials for tissue regeneration.Structure of poly[(R,S)‐3,3‐dimethylmalic acid].imageStructure of poly[(R,S)‐3,3‐dimethylmalic acid].

Synthesis and characterizations of new isotactic homopolyesters, statistical and block copolyesters derived of poly((S)‐3,3‐dimethylmalic acid) via the lactone route

“…16 Moreover, in the literature, the hydrolysis of atactic poly((R,S)-3,3-dimethylmalic acid) gave the corresponding (R,S)-3,3-dimethylmalic acid. 16,17 Anionic ring-opening polymerization of chiral a,a,b-trisubstituted-b-lactones leads to a large family of semicrystalline and isotactic poly((R)-3,3-dimethylmalic acid) derivatives having lateral functional group with high molecular weight (Scheme 2).…”

Polymeric Micelles and Nanoparticles from Block and Statistical Poly((RS)‐3,3‐dimethylmalic acid) Derivatives: Preparation and Characterization

“…These results confirm the well-controlled synthesis of the anionic polymerization of a,a,b-trisubstituted b-lactones previously described. [8] This synthetic statistical polymer 3 was deprotected by catalytic hydrogenolysis in the presence of palladium to furnish the corresponding polymer PDMMLAH 30 -co-He 70 4 with hydrophilic carboxylic acid functions (30%) as lateral chains (Scheme 2).…”

“…In a recent paper, we have proved that hydrolysis of poly((RS)-3,3-dimethylmalic acid) gave corresponding non-toxic low molecular weight compounds. [8] In parallel, the amphiphilic block copolyester PDMMLAH 50 -b-He 50 6 containing hydrophobic poly-(hexyl (RS)-3,3-dimethylmalate) segment and a hydrophilic poly(RS)-3,3-dimethylmalic acid) segment has been synthesized by living anionic ring-opening polymerization followed by a deprotection step. The copolymerization was realized with two different a,a,b-trisubstituted b-lactones with tetraethylammonium benzoate as anionic initiator.…”

“…In a recent publication, we demonstrated the living character of a,a,b-trisubstituted b-lactones anionic ringopening polymerizations. [8] In this paper, we report the synthesis of amphiphilic statistical and block copolyesters from (RS)-3,3-dimethylmalic acid and the preparation of nanoparticles and micelles from these systems. The typical dimensions and morphology of the obtained nanoparticles will be described and discussed, in conjunction with some preliminary study on the corresponding critical aggregation concentration (CAC) of obtained micelles.…”

New promising biodegradable polyesters derived from poly((R,S)-3,3-dimethylmalic acid) for cardiovascular applications

“…Indeed, (R)-3,3-dimethylmalic acid which is the final product of hydrolytic degradation of chiral PDMMLA is a natural and non-toxic product involved in the biosynthetic pathway of pantothenate. This metabolite is present in the synthesis of Coenzyme A and gives ketovaline by enzymatic oxidative reaction catalyzed by β,β--dimethyldehydrogenase (EC.1.1.1.84) [78,80,81,91,92] (Figure 3). [93].…”