Glycol esters cyclic

So far, various dicarboxylic acid derivatives, dicarboxylic acids, their activated and non-activated esters, cyclic acid anhydrides, and polyanhydrides have been polymerized with glycols through lipase catalysis to give polyesters. 

Various combinations of dicarboxylic acid derivatives and glycols enzymatically afforded polyesters under mild reaction conditions. Dicarboxylic acids as well as derivatives, activated and non-activated esters, cyclic acid anhydride, and polyanhydrides, were found to be useful as monomer for the enzymatic synthesis of polyesters. 

Chiral [160, l70, l80]phosphomonoesters and ATPy[l60, l70, lsO] have been synthesized by Knowles and associates, who devised the procedure outlined in Fig. 19 [51-55], The procedure has been used to synthesize phenyl[160, l70, l80]phos-phate and 2-[160,170,180]phospho-D-glycerate as well as the propylene glycol ester shown. The starting cyclic adduct was prepared by reaction of (— )-ephedrine with P17OCl3, giving a separable mixture of 2-chloro-l,3,2-oxazaphospholidin-2-ones whose chemistry had been described [56], The major isomer was converted to (/ p)-l-[160, nO,180]phospho-1,2-propanediol and (Sp)-ATPy[l60, nO, lsO] by the reactions shown. The stereochemistry at each step of the synthesis was well prece-dented in the literature nevertheless, the configurations were verified by independent methods described in the next section. 

CAS 108-32-7 EINECS/ELINCS 203-572-1 Synonyms Carbonic acid, cyclic propylene ester Carbonic acid, 1,2-propylene glycol ester 1,3-Carbon dioxypropane Cyclic methyleth-ylene carbonate Cyclic propylene carbonate Cyclic 1,2-propylene carbonate 1,3-Dioxolan-2-one, 4-methyl Dipropj ene carbonate 4-Methyl-1,3-dioxolan-2-one 1-Methyl ethylene carbonate 1,2-Propanediol carbonate 1,2-Propanediyl carbonate 1,2-Propylene carbonate Propylene glycol cyclic carbonate Classification Qrganic compd. carbonic acid ester Empirical C,HsQ,... 

Ethylene glycol brassylate cyclic diester Ethylene undecane dicarboxylate Tridecanedioic acid cyclic ethylene glycol diester 1,13-Tridecanedioic acid, 1,2-ethanediol ester 1,13-Tridecanedioic acid ethylene ester... 

Propylene carbonate CAS 108-32-7 EINECS/ELINCS 203-572-1 Synonyms Carbonic acid, cyclic propylene ester Carbonic acid, 1,2-propylene glycol ester 1,3-Carbonyl dioxypropane Cyclic methylethylene carbonate Cyclic propylene carbonate... 

Glycol esters from cyclic orthocarboxylic acid esters C... 

Maleic acid and phthalic acid are used as oligoester components together with bivalent alcohols (e.g., ethylene glycol, 1,4-butanediol) as co-condensation partners. Crosslinking is achieved by copolymerization of styrene, vinyl acetate, diallyl phthalate, acrylonitrile or acrylic ester. Cyclic structures impart a higher glass transition temperature. The aliphatic glycols in the... 

Lipase-Catalyzed Polymerization of Dicarboxylic Acids or Their Derivatives. Enzymatic synthesis has been achieved via various combinations of dicarboxylic acid derivatives and glycols. As to the diacid monomer, dicarboxylic acids, activated and nonactivated esters, cyclic acid anhydrides, and polyanhydrides were enzymatically reacted with glycols under mild reaction conditions. 

Carbonates and Related Derivatives Other Carboxylate Esters Esters ofNon-Carboxylic Acids OF GLYCOL SYSTEMS Cyclic Acetak, Ketak, and Orthoesters... 

Selective electrochemical detection of over Na was achieved by using gold electrodes functionalized with bis-thioctic ester-terminated derivatives of oligoethylene glycol by cyclic voltammetry and impedance spectroscopy. ... 

Another method for the hydroxylation of the etliylenic linkage consists in treatment of the alkene with osmium tetroxide in an inert solvent (ether or dioxan) at room temperature for several days an osmic ester is formed which either precipitates from the reaction mixture or may be isolated by evaporation of the solvent. Hydrolysis of the osmic ester in a reducing medium (in the presence of alkaline formaldehyde or of aqueous-alcoholic sodium sulphite) gives the 1 2-glycol and osmium. The glycol has the cis structure it is probably derived from the cyclic osmic ester ... 

A classical method for the vicinal hydroxylation of a double bond involves treatment with osmium tetroxide to give a cyclic ester, followed by reductive cleavage to the glycol ... 

However, the cyclic-intermediate mechanism cannot account for all glycol oxidations, since some glycols that cannot form such an ester (e.g., 12) are nevertheless cleaved by lead tetraacetate... 

The mechanism of oxidation probably involves in most cases the initial formation of a glycol (15-35) or cyclic ester,and then further oxidation as in 19-7. In line with the electrophilic attack on the alkene, triple-bonds are more resistant to oxidation than double bonds. Terminal triple-bond compounds can be cleaved to carboxylic acids (RC=CHRCOOH) with thallium(III) nitrate or with [bis(trifluoroacetoxy)iodo]pentafluorobenzene, that is, C6F5l(OCOCF3)2, among other reagents. 

It is clear then that more than one mechanism is operative for glycol fission. In the case of c -cyclopentanediols and camphanediols a cyclic ester is a necessary intermediate. For tra/js-decalin-9,10-diol a non-cyclic mechanism must operate which cannot function for cholestane-3/ ,6j8,7a-triol and is inefficient for /rans-camphanediols. It is pertinent that while the fission of glycols capable of forming cyclic esters proceeds several hundred times faster in benzene than in acetic acid, the reactions of trans-decalin-9,10-diol and tra/ij-hydrindane-l,6-diol are 4-5-fold slower in benzene . ... 

The most widely used reagent for oxidation of alkenes to glycols is osmium tetroxide. Osmium tetroxide is a highly selective oxidant that gives glycols by a stereospecific syn addition.39 The reaction occurs through a cyclic osmate ester that is formed by a [3 + 2] cycloaddition.40... 

Lipase CA catalyzed the polymerization of cyclic dicarbonates, cyclobis (hexamethylene carbonate) and cyclobis(diethylene glycol carbonate) to give the corresponding polycarbonates [105]. The enzymatic copolymerization of cyclobis(diethylene glycol carbonate) with DDL produced a random ester-carbonate copolymer. As to enzymatic synthesis of polycarbonates, reported were polycondensations of 1,3-propanediol divinyl dicarbonate with 1,3-propanediol [110], and of diphenyl carbonate with bisphenol-A [111]. 

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