Synthesis of polyesters having pendant ester groups by ring-opening polymerization of 4-methoxycarbonyl-2,6-dioxabicyclo[2.2.2]octan-3-one

Okada, Masahiko; Sumitomo, Hiroshi; Atsumi, Miharu; Hall, H. K.

doi:10.1021/ma00172a006

Cited by 16 publications

(3 citation statements)

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“…Identification of the product was based on 1 H NMR, IR, and mass spectra. Attempts to carry out ring-opening polymerization on 2,5-DBO under various conditions failed to give a polymer, perhaps because of insolubility …”

Section: Resultsmentioning

confidence: 99%

“…Attempts to carry out ringopening polymerization on 2,5-DBO under various conditions failed to give a polymer, perhaps because of insolubility. 55 In sharp contrast, the isomeric 2,6-DBO has eluded us (Scheme 3). The synthesis of 1-methyl-2,6-DBO was carried out without difficulty following the literature procedure previously reported by Connors et al 45 The synthesis is based on the condensation of vinyl ketone and alkyl malonate esters, monosubstituted or unsubstituted at C2, followed by cyclization under basic conditions using ammonia or primary amines.…”

Section: Resultsmentioning

confidence: 99%

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Synthesis and NMR Studies of Activated Derivatives ofcis- andtrans-5-Amino-6-oxopiperidine-2-carboxylic Acid and the Corresponding Bicyclic Dilactam 2,5-DBO: Potential Building Blocks for Stereoregular Polyamides and Peptides

et al. 1999

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Presented here are the syntheses of bicyclodilactams as precursors of polymeric lactams. A new preparation for the 2,5-diazabicyclo[2.2.2]octa-3,6-dione was developed. The four possible dimers were prepared from the N-protected cis- and trans-5-amino-6-oxopiperidine-2-carboxylates (Apc's). Base treatment of the trans activated ester led to the polymer. Synthesis of the isomeric 2,6-diazabicyclo[2.2.2]octan-3,5-dione was not successful even under conditions in which substituted compounds were found. From the 1H NMR spectral data for the monomers and dimers, we concluded that the H−H coupling constants for the cis- and trans-Apc monomers are consistent with the low-energy pseudo-chair conformations inferred from structures optimized at the B3PW91/6-31G* level of density functional theory. The two-dimensional NMR spectra of the oligomers give no evidence for β-turn formation in DMSO-d 6.

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Synthesis and NMR Studies of Activated Derivatives ofcis- andtrans-5-Amino-6-oxopiperidine-2-carboxylic Acid and the Corresponding Bicyclic Dilactam 2,5-DBO: Potential Building Blocks for Stereoregular Polyamides and Peptides

et al. 1999

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“…Hall and Okada systematically investigated the ROP of bicyclic lactones. [47][48][49][50][51][52][53][54][55] Recently, several other bicyclic lactones have also been synthesized and polymerized to generate high thermally stable polyesters with good mechanical properties and potential closed-loop recycling of monomers (Scheme 1). [55][56][57][58][59] The ROP of oxygen-containing bicyclic lactones (Scheme 1, VI-VIII) exhibits different polymerization behavior.…”

Section: Introductionmentioning

confidence: 99%

High-T_g PLA copolymers via base-catalyzed transesterification of PLA with 2,5,7-trioxabicyclo[2.2.2]octan-6-one

Zhou,

Guo,

Yang

et al. 2024

Polym. Chem.

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Spontaneous hydrolytic degradability of copolyesters having tetrahydropyran rings in their backbones

Okada

Ito

Aoi

et al. 1994

J of Applied Polymer Sci

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SYNOPSISHomo-and copolyesters, containing 2,5-linked tetrahydropyran rings in their backbones, were prepared by cationic ring-opening polymerization of bicyclic lactones, 2,g-dioxabicyclo [ 2.2.21 octan-3-one ( 1 ), and its 4-methoxy-carbonyl and 4-benzyloxycarbonyl derivatives ( 3 and 4 ) . Copolyesters, having pendant carboxyl groups, were derived from the copolymers containing 4 as one of the comonomers by the catalytic hydrogenolysis of the pendant benzyloxyxarbonyl groups. Copolyesters, containing both 2,5-linked and 2,6-linked tetrahydropyran rings in the main chains, were obtained by the copolymerization of 1 with 6,8-dioxabicyclo [ 3.2.11 octan-7-one ( 13 ) , which is a structural isomer of 1. Spontaneous hydrolytic degradability of these polyesters was investigated in a phosphate buffer solution (pH 7.5) at 27°C. The degradability of the polyesters markedly depended on the molecular structure: hydrophobic pendant groups retarded the hydrolytic degradation, whereas hydrophilic pendant groups accelerated it. In particular, a small amount of pendant carboxyl groups significantly enhanced the hydrolytic degradability of the copolyesters from 1. Polyesters, containing 2,6-linked tetrahydropyran rings in their backbones, underwent hydrolytic degradation more readily than those entirely consisting of 2,5-linked tetrahydropyran rings. INTRODUCTIONPollution by wasted plastics is one of the major factors that are worsening the ecological environment on the earth. There are two approaches to solving this troublesome problem: one is the material design of readily recyclable polymers; the other is the development of spontaneously degradable polymeric materials. As for the latter approach, one of the most promising materials is a class of photodegradable polymers. A variety of photodegradable polymers have been designed and synthesized, and some of them are commercialized.' Polymers, which are spontaneously hydrolyzable under neutral conditions to yield harmless low molecular weight compounds, would be of practical value if they were * To whom correspondence should be addressed. CCC OOZ1-8995/94/061035-09 readily processable and had the desirable mechanical and thermal properties. Of particular importance are biodegradable polymers, which are hydrolyzed and catabolized by microorganisms in a natural environment.On the other hand, from the viewpoint of biomedical materials, considerable attention has been directed toward spontaneously hydrolyzable, biodegradable, synthetic polymers, especially poly (a-hydroxy acid) s, such as poly (glycolic acid), poly ( lactic acid), and their analogues.2 Since the hydrolysis rates of these polyesters are relatively low, because of their high crystallinity and low hydrophilicity, several biodegradable polyesters with pendant carboxyl groups have been synthesized in order to impart higher hydrophilicity. Lenz et al.3'4 prepared homo-and copolymers of p-malic acid and its alkyl esters by ring-opening polymerization of benzyl malolactonate, followed by hydrogenolytic debenzylation. O...

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Synthesis of polyesters having pendant ester groups by ring-opening polymerization of 4-methoxycarbonyl-2,6-dioxabicyclo[2.2.2]octan-3-one

Cited by 16 publications

References 10 publications

Synthesis and NMR Studies of Activated Derivatives ofcis- andtrans-5-Amino-6-oxopiperidine-2-carboxylic Acid and the Corresponding Bicyclic Dilactam 2,5-DBO: Potential Building Blocks for Stereoregular Polyamides and Peptides

Synthesis and NMR Studies of Activated Derivatives ofcis- andtrans-5-Amino-6-oxopiperidine-2-carboxylic Acid and the Corresponding Bicyclic Dilactam 2,5-DBO: Potential Building Blocks for Stereoregular Polyamides and Peptides

High-T_g PLA copolymers via base-catalyzed transesterification of PLA with 2,5,7-trioxabicyclo[2.2.2]octan-6-one

Spontaneous hydrolytic degradability of copolyesters having tetrahydropyran rings in their backbones

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Synthesis of polyesters having pendant ester groups by ring-opening polymerization of 4-methoxycarbonyl-2,6-dioxabicyclo[2.2.2]octan-3-one

Cited by 16 publications

References 10 publications

Synthesis and NMR Studies of Activated Derivatives ofcis- andtrans-5-Amino-6-oxopiperidine-2-carboxylic Acid and the Corresponding Bicyclic Dilactam 2,5-DBO: Potential Building Blocks for Stereoregular Polyamides and Peptides

Synthesis and NMR Studies of Activated Derivatives ofcis- andtrans-5-Amino-6-oxopiperidine-2-carboxylic Acid and the Corresponding Bicyclic Dilactam 2,5-DBO: Potential Building Blocks for Stereoregular Polyamides and Peptides

High-Tg PLA copolymers via base-catalyzed transesterification of PLA with 2,5,7-trioxabicyclo[2.2.2]octan-6-one

Spontaneous hydrolytic degradability of copolyesters having tetrahydropyran rings in their backbones

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High-T_g PLA copolymers via base-catalyzed transesterification of PLA with 2,5,7-trioxabicyclo[2.2.2]octan-6-one