Mono-esters

Electrolysis, under similar conditions, of a mixture of two carboxylic acids RCOOH and R COOH leads, in addition to normal coupling products R—R and R —R, to cross coupling R—R. If a mixture of a saturated carboxylic acid and a half ester of an ato-dicarboxylic acid is electrolysed, there are three main products, viz., a hydrocarbon (I), a mono-ester (II), and a di-ester (HI) and these are readily separable by distillation. Some unsaturated ester (IV) is often present in small quantity. 

AH the common monobasic (107) and dibasic esters (108) of tetrahydrofurfuryl alcohol have been prepared by conventional techniques the dibasic esters and some of the mono esters are effective as primary or secondary plasticizers for vinyl polymers. Tetrahydrofurfuryl acrylate [2399-48-6] and methacrjiate [2455-24-5] specialty monomers, have been produced by carbonylation (nickel carbonyl and acetylene) of the alcohol (109) as weU as by direct esterification (110—112) and ester interchange (111). 

Ozone. Most acetals are subject to cleavage with ozone, giving a mono ester of the original diol. 

Di- and mono-esters of phthalic acid, an ortho-dicarboxylic acid derivative of benzene. These compounds are widely used as industrial plasticizers to coat polyvinylchloride surfaces of plastics used in food packaging and medical devices (iv drip bags, blood storage bags, etc.) and are common environmental contaminants. Several phthalate mono-esters are peroxisome proliferator chemicals and can activate the peroxisome proliferator-activated receptor PPAR. 

C H2 OH>2 CHN02 (liq)+C H 3 COOHQiq) - (CH200CCH3)2CHN02 0iq), 3) selective oxidation to a mono ester olefin using mild conditions such as dil aq KMn04 ... 

Scheldt and co-workers have nsed their in situ hydroxyazolium oxidation strategy to allow the desymmetrisation of diol 249 using chiral triazolium salt 187, giving mono-ester 250 in 80% ee (Scheme 12.55) [99]. 

Table 12.6 Comparison of characteristic properties of mono-ester and multi-ester compounds [114]...

Accelerations (or decelerations) imposed by the cycloamyloses on the rate of an intramolecular reaction may be derived from a conformational effect. The rate of an intramolecular reaction depends not only on the proximity of the reactive groups but also on their relative orientation. For example, Bruice and Bradbury (1965) have shown that the rates of formation of cyclic anhydrides from mono esters of 3-substituted glutaric acids depend on the size of the substituent at the 3-position. This observation was interpreted as a change in the ground state population of reactive and non-reactive conformers as the 3-substituents are varied (Scheme IX). Reason-... 

In the case of mono-ester substituted pyrroles (e.g., 68) wherein relatively unstable dianions likely to deprotonate ammonia might be produced, the authors instead utilized an excess of (MeOCH2CH2)2NH as a substitute for ammonia. It was felt that upon in situ formation of (MeOCH2CH2)2NLi, this base would be unable to protonate the dianion <00TL1331>. Remarkably, quenching the reduction reactions with benzoyl chloride affords P-keto esters (e.g., 69, R = COPh), a reaction that does not occur when conducted in liquid ammonia. 

In a corresponding manner, the mono-esters of P(III) systems can be produced by controlled reaction of the P(III) halides with the appropriate hydroxyl compound. Significantly better yields are obtained for the aryl esters (from phenols — Equation 4.3) than for alkyl esters (from alcohol), and primary alcohols provide better yields than do secondary alcohols.5 6... 

But the reaction conditions are still more complicated because the stoichiometry of reaction might alter. Many greases and oils comprise the esters of long-chain fatty acids. The hydrolysing reaction between NaOH and an ester such as ethyl ethanoate proceeds with a stoichiometry of 1 1, but a tri-ester, such as most natural oils (e.g. olive oil or sunflower oil), occurs with a 1 3 stoichiometry, consuming one hydroxide ion per ester bond. Clearly, the hydroxide will be consumed more quickly when hydrolysing a triester than a mono-ester. The rate depends on the stoichiometry of reaction. 

In the absence of an oxidation agent, the reaction is derived to monoalkoxy-carbonylation provided the Pd metal center is stabilized by surrounding ligands. This strategy, first illustrated in 1976 by Knifton with the complex [PdCl2(PPh3)2], has been extensively developed since then [55,56]. Various terminal aliphatic alkenes are converted into the corresponding mono esters... 

A useful review of the chemistry of a-aminophosphonic acids has been published.47 Treatment of a-aminomethylphosphonic mono-esters with bromoacetyl halides... 

When 1,2-diols are subjected to the same reaction conditions required for the formation of sulphonic esters, oxiranes are produced [27]. Presumably, the mono ester is initially formed and, under the basic conditions, intramolecular elimination occurs to produce the oxirane. Partial hydrolysis and ring-closure of a,p-di(tosyloxy) compounds under basic phase-transfer catalytic conditions provides a convenient route to carbohydrate oxiranes [e.g. 28, 29]. Oxiranes have been produced by an analogous method via carbonate esters from partially protected carbohydrates [30],... 

Whilst many biochemicals are mono-esters of phosphoric acid, the nucleic acids DNA and RNA (see Section 14.2) provide us with good examples of diesters. A short portion of one strand of a DNA molecule is shown here the most significant difference in RNA is the use of ribose rather than deoxyribose as the sugar unit. 

Species differences in the metabolism of di(2-ethylhexyl) phthalate have been reported and attempts have been made to explain the susceptibility of animals to di(2-ethylhexyl) phthalate-induced hepatic peroxisome proliferation based on their metabolic profiles (Doull et al., 1999). As mentioned above, the bulk of a di(2-ethylhexyl) phthalate dose is absorbed as the mono-ester, mono(2-ethylhexyl) phthalate, and following absorption this metabolite is subjected to extensive oxidative metabolism mediated by cytochrome P450 enzymes (Albro Lavenhar, 1989 Astill, 1989 Huber et al., 1996 Doull et al., 1999). The metabolism of mono(2-ethylhexyl) phthalate has been summarized by Doull et al. (1999) as follows (see Figure 1) ... 

Depending on the identity, number and position of the acyl residues, these acids may be divided into the following groups mono-esters of caffeic, p-coumaric and ferulic acid di-, tri- and tetra-esters of caffeic acid [14,15] mixed di-esters of caffeic and ferulic acid or caffeic and sinapic acid [16] mixed esters of caffeic acid with dibasic aliphatic acids (e.g., oxalic, succinic) [17]. 

Unchanged mono ester may be recovered by acidification of the carbonate washings, followed by extraction with ether. 

Aerosol A-102 Mono-ester sulfosuccinate surfactant Cytec... 

Mono esters of dicarboxylic acids.1 Aliphatic straight-chain dicarboxylic acids when adsorbed on alumina react with diazomethane to form monomethyl esters in quantitative yield. Terephthalic acid, isophthalic acid, and 1,4-cyclohexanedi-carboxylic acid are also converted selectively to the monomethyl esters. However, phthalic acid does not show any enhanced selectivity under these conditions. Evidently selectivity for monoesterification results from adsorption of one of the acid groups on alumina. 

The reason that dialkyl sulfates seldom are prepared by direct reaction of the alcohol with H2S04 is that the mono esters react rapidly on heating to eliminate sulfuric acid and form alkenes, as explained in Section 15-5C. 

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