Quinic acid oxidation

Biochemical Routes. Enzymatic oxidation of benzene or phenol leading to dilute solution of dihydroxybenzenes is known (62). Glucose can be converted into quinic acid [77-95-2] by fermentation. The quinic acid is subsequently oxidized to hydroquinone and -benzoquinone with manganese dioxide (63). 

These useful compounds have played a central role in both theoretical and practical organic chemistry since the 1840s. In 1838 quinic acid [36413-60-2] (1) was oxidized to 1,4-benzoquinone (2) with manganese dioxide (1). 

Gallic acid is present in tea leaf and is a known reactant during the complex enzymatic and organochemical reactions that occur when tea components are oxidized.51 The gallic and quinic acids originate via the shikimate/arogenate pathway. The key enzymes in shikimic acid biosyn-... 

Starting from quinic acid, a highly substituted, cis-afi unsaturated nitrile oxide has been synthesized and used in a 1,3-dipolar cycloaddition, to afford a precursor of the cis -decalin system of branimycin (468). 

Quinone may be prepared by the oxidation of aniline with dichromate or manganese dioxide and sulfuric acid.1 This is a more feasible commercial method than the one given. However, the oxidation of hydroquinone is more rapid and convenient and, hence is more desirable for use in the laboratory. Various materials have been oxidized by chemical means to give quinone they are quinic acid,2 hydroquinone,3 benzidine,4 -phenylene-diamine,5 sulfanilic acid,6 / -phenolsulfonic acid,7 arbutin,8 aniline black,9 and the leaves of various plants.10 Quinone is also formed by several other methods by the fermentation of fresh grass 11 by the action of iodine on the lead salt of hydroquin-... 

Chinese white chem A term used in the paint industry for zinc oxide and kaolin used as a white pigment. Also known as zinc white. chTn nez wTt chinic acid See quinic acid. kin ik as ad chinoldine See quinoidine. ki noT.den chinone See quinone. kin on ... 

Following the structure proof of the alkaloids by degradation, Hughes et al. (.18) synthesized (—)-0-methylcryptaustoline iodide (14) by methods elaborated by Schopf and Robinson. ( )-Laudanosine was resolved by quinic acid (79), and (S)-(-)-laudanosine was 0-demethylated by Schopf s procedure, oxidized by chloranil, and remethylated to afford chiral 14 as the iodide in 40% yield. Their product had the same specific rotation and melting point as O-methylcryp-taustoline iodide obtained from the natural alkaloid 1. Methine derivatives obtained from synthetic and natural compounds had identical optical properties. 

The bacterium Klebsiella pneumonia can use quinic acid as a carbon source for its growth the first step here is oxidation of quinic acid to 3-deoxyhydroquinate (DHQ), which is catalyzed by the enzyme quinic acid dehydrogenase. Actually, thermodynamics predicts that the reverse reaction is favored. So if a second bacterium, which made DHQ, had inserted into it the gene for the dehydrogenase, and if this second bacterim did not normally metabolize quinic acid, then this would result in the second organism synthesizing quinic acid from DHQ. 

Fischer and Dangschat116 also applied lead tetraacetate oxidation to locate the position of a single, free hydroxyl group on a six-membered ring. Thus, the mono-O-isopropylidene acetal of quinic acid lactone (XLI) was... 

Hydro-quinol, 1-4-Di-hydroxy Benzene.—The third isomeric dihydroxy benzene, viz., the para compound, i-4-di-hydroxy benzene, is known as hydro-quino or hydro-quinone. The latter name is derived from its relation to quinone (p. 636) from which it is obtained on reduction and which it yields on oxidation. Both hydro-quinol and quinone derive their names from the fact that they are obtained by the oxidation of quinic acid, an acid derived from the alkaloid quinine. The phenol is found in various plants or may be obtained from them by the hydrolysis of glucosides present, e.g., arbutin, which is a glucoside hydrolyzing into glucose and hydro-quinol. 

Benzo-quinone.—Benzoquinone, or more commonly, simply quinone, is the most common and important of the quinones derived from benzene. Other important quinones will be met with when we study derivatives of the more complex hydrocarbons napthalene and anthracene. Benzoquinone is the one we have used as our example in the above discussion and it is the para-di-keto benzene. It was first obtained by the oxidation of quinic acid, which in turn was obtained from quinine, hence its name. It may also be prepared by oxidizing... 

Many Crv complexes are difficult to crystallize due to their low stabilities in solution. In such cases, XAFS spectroscopy can be used for structural characterization of the complexes (which can be isolated as amorphous solids or snap-frozen in solutions).11 Recently, this method has been applied for the first detailed characterizations of Crv complexes with natural ligands, quinic acid (49c)148 and L-alanine (55).154 The Cr=0 bond lengths in (45)-(57) vary from 1.52 A to 1.61 a.57,58,141-154 The values of Cr—O bond lengths in the complexes, containing only O-donors, can be used for the determination of the oxidation state of Cr by the bond valence sum method.143... 

There is a similarity between L-shikimic acid and L-quinic acid in that the quasi-axial hydroxyl group on C-5 in L-shikimic acid corresponds to the axial hydroxyl group in L-quinic acid. This quasi-hydroxyl group, like the corresponding axial hydroxyl group in L-quinic acid, is more readily oxidized catalytically in 5 hr. at room temperature in the presence of Adams catalyst, to give dehydro-L-shikimic acid (62). A amilar oxidation supphes an important intermediate in the biosynthesis of aromatic compounds. 

Hydroquinone—Paradioxg-Oenzene——1—4—is formed by fusing paraiodo-phenol with KHO at 180° 356° F.), by dry distillation of oxysalicylic acid or of quinic acid, and by the action of reducing agents on q at none It forms colorless, rhombic prisms, which fuse at 169° (336°.2 F.). Readily soluble in water, alcohol, or ether. Its aqueous solution is turned red-brown by XH,HO. Oxidizing agents convert it into quinone. 

Quinone—C,H,(OOy —is tlie representative of a number of similar compounds, denvable from the aromatic hydrocarbons. It is produced by the oxidizing action of MnO + H SO, or of dilute chromic acid, upon quite a number of para-benzene derivatives but best by the limited oxidation of quinic acid. 

Oxidative interconversion of cyclitols and derivatives into acyclic, di-carboxylic acids has been widely used for structural elucidation in this series. Early applications of the procedure helped determination of the constitution of shikimic and quinic acids for example, cleavage of the 1,2,3-triol grouping of methyl dihydroshikimate (35) produced a dialdehyde (36), which was oxidized with bromine water to the (known) degradation end product, tricarballylic acid (37). This approach to structural problems has proved particularly successful for determining the configuration of glycosides and related compounds. 

Benzoquinones. Derivatives of p- or o-benzoqui-nones belonging to the group of quinone pigments that are widely distributed in nature. p-B. itself was recognized in 1838 by Woskresensky (student of Liebig) as the oxidation product of quinic acid and named qui-noyl the name quinone was introduced by Berzelius. The chromophore of B. consists of two carbonyl groups which are in conjugation with two double bonds. 

The C10-C18 fragment 295, prepared from the optically pure monoepoxy alcohol, was functionalized to the dithiane phosphine oxide 296. The other fragment 297 prepared from quinic acid was treated with LiOOH to remove the chiral auxiliary, and the resulting acid was transformed into the aldehyde 298... 

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