Muconic Acid Derivatives Research Articles

Molecular Design and Polymer Structure Control Based on Polymer Crystal Engineering. Topochemical Polymerization of 1,3-Diene Mono- and Dicarboxylic Acid Derivatives Bearing a Naphthylmethylammonium Group as the Countercation

The topochemical polymerization of the alkylammonium salts of (Z,Z)-, (E,Z)-, and (E,E)-1,3-diene mono- or dicarboxylic acids, i.e., of the muconic and sorbic acid derivatives, is described from the viewpoint of polymer crystal engineering. Not only the (Z,Z)- but also the (E,E)-derivatives polymerize to give a high molecular weight polymer in the crystalline state under UV irradiation when a naphthylmethylammonium moiety is introduced to these monomers as the countercation. NMR spectroscopy confirms the formation of the stereoregular meso- or erythro-diisotactic-trans-2,5-polymer during the polymerization, irrespective of the configuration of the monomers and the structure of the substituents. The single-crystal structure analysis of the naphthylmethylammonium salt of sorbic acid reveals the stacking of the diene moieties in the columns formed in the crystals, favorable for the topochemical polymerization. The photopolymerization reactivity and the stereochemistry of the resulting polymers are determined...

Porphyrin-o-quinones as Model Systems for Electron Transfer and Catecholase Reactions

Various porphyrin-o-quinones 1−8 were prepared as model compounds for electron transfer reactions. The synthesis of these compounds could only be accomplished by using o-quinone components stabilized by sterically demanding substituents in the o,o′-positions and by using protected catechol aldehydes for the initial porphyrin condensation step. The stability of the target compounds strongly depends on the steric influence of substituents on the o-quinone, which are necessary to stabilize the o-quinones. To test this steric influence we synthesized the porphyrin-o-quinones both without and with methyl and tert-butyl groups and investigated the influence of the bridging position on the reactivity. The 1H- and 13C-NMR spectroscopic characteristics of all compounds are given. The electron transfer properties were determined using optical spectroscopy and cyclic voltammetry. The free base porphyrin-o-quinone 1 with two tert-butyl groups in the o,o′-positions of the quinone readily underwent degradation reactions to muconic acid derivatives similar to those observed in catecholase reactions. Nevertheless, this is the first report of such reactions that do not involve the addition of metal-containing catalysts. The respective zinc(II) complex 6 and the two separated components tetraphenylporphyrin 26 and 3,6-di-tert-butyl-o-quinone (27) did not undergo this reaction, and we surmise a photochemical mechanism that depends on the steric demand of the o-quinone.

First example of the topochemical polymerization of the (E,E)-muconic acid derivative

First example of the topochemical polymerization of the (E,E)-muconic acid derivative

First direct aromatic ring cleavage of phenols related to vanillin into muconic acid derivatives catalyzed by a microorganism

Incubations of Pseudomonas cepacia AC1100 resting cells with 5-bromo-, 5-chlorovanillin and vanillin yield the muconic compounds resulting from direct phenol ring cleavage of the COHCOMe bond.

Catalytic properties of polymeric copper-amine-cellulose complexes

Several Cu-amine-cellulose polymers, where the amine is 1,3-diamino-propane, 3,3'-dipropylamino- N-methyl-dipropylamine or triethylenetetramine, have been prepared and characterized by chemical analysis, UV—VIS and IR spectroscopy. They have been shown to be efficient catalysts for the selective and controlled autoxidation of a variety of organic systems in nonbasic solvents such as CHCl 3, including the oxidative polymerization of phenols with very little dibenzoquinone as a product, oxidation of catechols to o-benzoquinones without further oxidation to muconic acid derivatives, benzoin to benzil without further oxidation to benzoic acid, oxidative coupling of terminal acetylenes to yield 1,3-diynes, oxidative halogenation of ketones and oxidative coupling of aromatic amines and aliphatic aldehydes. These complexes are easily prepared and are excellent reusable heterogeneous catalysts for a variety of autoxidations of organic substrates.

ChemInform Abstract: FERRIC NITRILOTRIACETATE: AN ACTIVE‐CENTER ANALOG OF PYROCATECHASE

AbstractEs bekannt , daß Pyrocatechase, eine Nicht‐Häm‐Fe(III)‐Dioxygenase, die Intradiol‐Ringspaltung von Brenzkatechin durch O2 katalysiert.

Radical polymerization of muconic acid and ethyl muconate

AbstractMuconic acid (Mu‐acid) was found to polymerize to trans‐1,4‐poly(Mu‐acid) with the use of azobisisobutyronitrile (AIBN) as an initiator. Similarly, a muconic acid derivative, ethyl muconate (EMu), was readily polymerized through a trans‐1,4 addition mechanism by the use of a radical or anionic catalyst, but did not polymerize when a cationic catalyst such as boron trifluoride etherate was used. Moreover, the copolymerization of Mu‐acid and EMu with various comonomers such as styrene, acryronitrile, and 2‐vinylpyridine was carried out and Q–e values of Mu‐acid and EMu are discussed. These substituted diene monomers always polymerized through trans‐1,4 addition with all catalysts and any comonomers.

Oxidative Ring Cleavage of 3,5-Di-t-butyl-catechol and -o-benzoquinone by Base-Catalyzed Oxygenation

Abstract The oxygenation of 3,5-di-t-butyl-catechol and -o-benzoquinone in t-BuOH with t-BuOK leads to the direct oxidative cleavage of the C1–C2 bond affording 2,4-di-t-butyl-4-carboxymethyl-2-buten-4-olide, a muconic acid derivative. The reaction is rationalized by assuming the reaction of 3,5-di-t-butyl-o-benzosemiquinone with oxygen.

Action of a Ring-Cleaving Enzyme in Preventing Oxidative Darkening of Juices

Catechol type compounds such as chlorogenic acid are the natural substrates for polyphenol oxidase in fruit juices, and these compounds are converted by the enzyme to polymers that result in a dark juice. When apple juice, in the presence of ascorbate, was treated with the enzyme protocatechuate 3,4-dioxygenas, darkening was permanently prevented since the enzyme oxidatively cleaves the benzene ring of the substrates to yield branched chain derivatives of muconic acid. The muconic acid derivatives cannot participate in the polyphenol oxidase browning reaction.

Topochemistry. Part XXIII. The solid-state photochemistry at 25° of some muconic acid derivatives

trans,trans-Muconic acid, its monomethyl ester, and cis,cis-isomer, all of which crystallise in cells with shortest axes of 4 A, react in the solid state on irradiation with λ > 290 mµ. At room temperature all give vinyl-substituted cyclobutanes of symmetry m, the configuration of which reproduces the geometry of the monomer molecules both in the attachment of the ring substituents and in the configuration of the vinyl side-chain. The all-trans-acid and its monomethyl ester give, in addition to dimers, various amounts of oligomers which, according to the spectroscopic evidence, are formed by both 1,4- and 1,2-addition of the butadiene chains. Dimethyl trans,trans-muconate, which does not crystallise in a 4 A cell, is stable to λ > 290 mµ at 25°.