Tartaric acid Reduction

Figure 5.3. Effect of loading of Ru on enantioselectivity in the hydrogenation of ethyl acetoacetate into ethyl 3-hydroxybutyrate over Ru-silica catalysts modified with (2R,3R)-tartaric acid (reduction time 0.5 (upper curve) or 5 h (lower curve) crystallite sizes after 0.5h reduction time were 1.6 nm (at 1.5% Ru), 4.5 nm (at 4.2% Ru) or 8 nm (at 11.5% Ru) (according to Vedenyapin et al. ).

Moreover, if acetonedicarboxylic acid monomethyl ester (190) is used as reactive acetone equivalent instead of acetonedicarboxylic acid (183) in the Robinson-Schbpf condensation, ( )-2-carbomethoxytropinone (193) can be obtained, which can be converted either into (-)-cocaine or (-h)-cocaine (36) in three subsequent steps (separation of both epimers of 193 via crystallization with either (-H)-tartaric acid or (-)-tartaric acid, reduction of the carbonyl group, and benzylation) (Scheme 11.44) [137]. 

CsHsO. Colourless, crystalline solid m.p. 115 C. Prepared by the dry distillation of tartaric acid or by reduction of itaconic or cilra-conic acids. Forms an anhydride when heated to 200"C. 

Acetophenone similarly gives an oxime, CHjCCgHjlCtNOH, of m.p. 59° owing to its lower m.p. and its greater solubility in most liquids, it is not as suitable as the phenylhydrazone for characterising the ketone. Its chief use is for the preparation of 1-phenyl-ethylamine, CHjCCgHslCHNHj, which can be readily obtained by the reduction of the oxime or by the Leuckart reaction (p. 223), and which can then be resolved by d-tartaric acid and /-malic acid into optically active forms. The optically active amine is frequently used in turn for the resolution of racemic acids. 

The original commercial source of E was extraction from bovine adrenal glands (5). This was replaced by a synthetic route for E and NE (Eig. 1) similar to the original pubHshed route of synthesis (6). Eriedel-Crafts acylation of catechol [120-80-9] with chloroacetyl chloride yields chloroacetocatechol [99-40-1]. Displacement of the chlorine by methylamine yields the methylamine derivative, adrenalone [99-45-6] which on catalytic reduction yields (+)-epinephrine [329-65-7]. Substitution of ammonia for methylamine in the sequence yields the amino derivative noradrenalone [499-61-6] which on reduction yields (+)-norepinephrine [138-65-8]. The racemic compounds were resolved with (+)-tartaric acid to give the physiologically active (—)-enantiomers. The commercial synthesis of E and related compounds has been reviewed (27). The synthetic route for L-3,4-dihydroxyphenylalanine [59-92-7] (l-DOPA) has been described (28). 

Methylsuccinic acid has been prepared by the pyrolysis of tartaric acid from 1,2-dibromopropane or allyl halides by the action of potassium cyanide followed by hydrolysis by reduction of itaconic, citraconic, and mesaconic acids by hydrolysis of ketovalerolactonecarboxylic acid by decarboxylation of 1,1,2-propane tricarboxylic acid by oxidation of /3-methylcyclo-hexanone by fusion of gamboge with alkali by hydrog. nation and condensation of sodium lactate over nickel oxide from acetoacetic ester by successive alkylation with a methyl halide and a monohaloacetic ester by hydrolysis of oi-methyl-o -oxalosuccinic ester or a-methyl-a -acetosuccinic ester by action of hot, concentrated potassium hydroxide upon methyl-succinaldehyde dioxime from the ammonium salt of a-methyl-butyric acid by oxidation with. hydrogen peroxide from /9-methyllevulinic acid by oxidation with dilute nitric acid or hypobromite from /J-methyladipic acid and from the decomposition products of glyceric acid and pyruvic acid. The method described above is a modification of that of Higginbotham and Lapworth. ... 

Unequivocal syntheses of cis- and mns-(i -decahydroquinoxalincs have been achieved by lithium aluminum hydride reduction of the corresponding cis- and trans-decahydroquinoxaIin-2-ones. The latter compounds were prepared by condensation of chloroacetic acid and cis- and trans-1,2-diaminocyclohexane, respectively. The resolution of frans-dUdecahydroquinoxaline was effected by use of first dibenzoyl-cZ-tartaric acid and then of dibenzoyl- -tartaric acid. "" (C/. p. 215.)... 

Different organic acids, primarily lactic acid, have been successfully used for decontamination of whole livestock carcasses, and the application of different organic acids used for decontamination has also been tested in the fruit and vegetable industry. Organic acids other than lactic acid that are known to have bactericidal effects are acetic, benzoic, citric, malic, propanoic, sorbic, succinic and tartaric acids (Betts and Everis 2005). The antimicrobial action is due to a reduction in the pH in the bacterial environment, disruption of membrane transport, anion accumulation or a reduction in the internal pH in the cell (Busta et al., 2001). Many fruits contain naturally occurring organic acids. Nevertheless, some strains, for example E. coli 0157, are adapted to an acidic environment. Its survival, in combination with its low infective dose, makes it a health hazard for humans. 

The enantioselective hydrogenation of prochiral substances bearing an activated group, such as an ester, an acid or an amide, is often an important step in the industrial synthesis of fine and pharmaceutical products. In addition to the hydrogenation of /5-ketoesters into optically pure products with Raney nickel modified by tartaric acid [117], the asymmetric reduction of a-ketoesters on heterogeneous platinum catalysts modified by cinchona alkaloids (cinchonidine and cinchonine) was reported for the first time by Orito and coworkers [118-121]. Asymmetric catalysis on solid surfaces remains a very important research area for a better mechanistic understanding of the interaction between the substrate, the modifier and the catalyst [122-125], although excellent results in terms of enantiomeric excesses (up to 97%) have been obtained in the reduction of ethyl pyruvate under optimum reaction conditions with these Pt/cinchona systems [126-128],... 

Surface modification of skeletal nickel with tartaric acid produced catalysts capable of enantiose-lective hydrogenation [85-89], The modification was carried out after the formation of the skeletal nickel catalyst and involved adsorption of tartaric acid on the surface of the nickel. Reaction conditions strongly influenced the enantioselectivity of the catalyst. Both Ni° and Ni2+ have been detected on the modified surface [89]. This technique has already been expanded to other modified skeletal catalysts for example, modification with oxazaborolidine compounds for reduction of ketones to chiral alcohols [90],... 

Small molecule crystallographers are familiar with these concepts, since it is routine to measure data at low temperature to improve precision by reduction of thermal motion, and structures are often done at multiple temperatures to assess the origins of disorder in atomic positions. Albertsson et al. (1979) have reported the analysis of the crystal structure of Z)(-l-)-tartaric acid at 295, 160, 105, and 35 K. Figure 22 shows the individual isotropic. S-factors for the atoms in the structure at each of these temperatures the smooth variation of B with T is apparent. Below 105 K, B is essentially identical for all atoms and is also temperature independent the value of B = 0.7 agrees well with the expected zero-point vibradonal value. However, even for this simple structure, not all of the atoms show B vs T behavior at high temperature which extrapolates to 0 A at 0 K. 

Sinou and coworkers evaluated a range of enantiopure amino alcohols derived from tartaric acid for the ATH reduction of prochiral ketones. Various (2R,iR)-i-amino- and (alkylamino)-l,4-bis(benzyloxy)butan-2-ol were obtained from readily available (-I-)-diethyl tartrate. These enantiopure amino alcohols have been used with Ru(p-cymene)Cl2 or Ir(l) precursors as ligands in the hydrogen transfer reduction of various aryl alkyl ketones ee-values of up to 80% have been obtained using the ruthenium complex [93]. Using (2R,3R)-3-amino-l,4-bis(benzyloxy)butan-2-ol and (2R,3R)-3-(benzylamino)-l,4-bis(benzyloxy)butan-2-ol with [lr(cod)Cl]2 as precursor, the ATH of acetophenone resulted in a maximum yield of 72%, 30% ee, 3h, 25 °C in PrOH/KOH with the former, and 88% yield, 28% ee, 120 h with the latter. 

Optically active icco-nucleosides of type 1.1 of 2-nitromidazole were prepared from tartaric acid ester by conversion to the dioxolan followed by reduction and acylation to give 1154, which was converted to 1155. Its coupling and deacylation gave 1156 (94MIP1). All the optically active isomers showed a radiation-sensitization effect equivalent to that of the racemate. 

The first described synthesis of the enantiomeric cetirizine employed resolution of a ( )-chlorobenzhydrylainine as the salt with tartaric acid. Later, an asymmetric synthesis was reported by the Corey group in 1996 (Scheme 7). The pivotal step involved a chiral oxazaborolidine (CBS)-catalyzed reduction of an unsymmetrical chlorobenzophenone with a Tt-chromium tricarbonyl group serving as an effective... 

Tartaric Acid. Quantitative measures of total tartrate are useful in determining the amount of acid reduction required for high acid musts and in predicting the tartrate stability of finished wines. Three procedures may be used. Precipitation as calcium racemate is accurate (85), but the cost and unavailability of L-tartaric acid are prohibitive. Precipitation of tartaric acid as potassium bitartrate is the oldest procedure but is somewhat empirical because of the appreciable solubility of potassium bi-tartrate. Nevertheless, it is still an official AO AC method (3). The colorimetric metavanadate procedure is widely used (4, 6, 86, 87). Tanner and Sandoz (88) reported good correlation between their bitartrate procedure and Rebeleins rapid colorimetric method (87). Potentiometric titration in Me2CO after ion exchange was specific for tartaric acid (89). 

Vanadium pentoxide becomes markedly photo-sensitive when immersed in glycerol, benzaldehyde, cinnamic aldehyde, cuminol, or aqueous mannitol solution, and exposed to light. It blackens and undergoes reduction, giving rise, initially, to hypovanadic oxide, VOg. With aqueous solutions of citric acid or tartaric acid carbon dioxide is evolved during the change.9... 

Fumaric acid has been prepared from bromosuccinic acid by heating with water,1 or dilute hydrobromic add,2 and by heating the acid above its melting point.3 It has also been prepared by heating malic acid,4 by transmutation of maleic acid 5 and by the reduction of tartaric acid with phosphorus and iodine.6 The procedure described is the most satisfactory for laboratory use, and is a slight modification of one recently described in the literature.7... 

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