CANNIZZARO Oxidation Reduction

CANNIZZARO Oxidation Reduction A redox reaction between two aromatic aldehydes (or an anomatic aldehyde ar formaldehyde to a mixture of alcohol and acid... 

CANNIZZARO Oxidation-reduction 58 CARROLL Allylalion 59 Castro 363... 

Cannizzaro reaction An internal oxidation-reduction reaction of aldehydes, carbamide Urea, carcinogenic Cancer causing. 

Phytochemical reduction must be regarded as a special case of oxidation-reduction. Since it is enzymatically conducted it should be distinguished from the analogously formulated Cannizzaro reaction. For this reason Neuberg, Hirsch and Reinfurth suggested the name dismutation for the physiological process, and in the last 25 years... 

CANNIZZARO, STANISLAO (1826-1910). Born in Italy, lie extended the research of Avogadro on the molecular concentration of gases and thus was able to prove the distinction between atoms and molecules. His investigations of atomic weights helped to helped lo make possible the discovery of the periodic law hy Mendeleyev. His research in organic chemistry led to the establishment of the Cannizzaro reaction involving the oxidation reduction of an aldehyde in the presence of concentrated alkali. 

Oxidation-reduction reactions similar to the Cannizzaro process are brought about in the living cell by certain enzyme systems. Numerous exanfples 7-8- 10 of these have been studied in vitro by the aid of tissue preparations, and certain of them 6 suggest possible application in preparative methods. The dismutation. of aldehydes in basic or neutral solution also has been effected by catalytic metals, such as nickel and platinum.11 12 It seems likely that there is a closer analogy between... 

Aldehydes can undergo an intermolecular oxidation—reduction (Cannizzaro reaction) in the presence of base to produce an alcohol and a carboxylic acid salt. Any aldehyde is capable of participating in such a reaction, however, it is more common for those containing no protons on the alpha carbon, for example... 

Intramolecular Oxidation-Reduction of Aldehydes (Cannizzaro) 2R.CCH0 + NaOH — R,CCOjNa + RjCCHjOH... 

Oxidation-reduction reactions similar to the Cannizzaro process are brought about in the living cell by certain enzyme systems. Numerous exam ples of these have been studied in vitro by the aid of... 

The oxidation-reduction process resembles a Cannizzaro reaction and probably proceeds by a similar hydride ion shift involving as acceptor the Schiff base coi jugate acid ... 

In general it is aldehydes of aromatic hydrocarbons and of heterocycles that can be subjected to this reaction, named after its discoverer the Cannizzaro reaction but there a similar oxidation-reduction, brought about by an enzyme, plays an important part in biological events in the cell. In the laboratory the Cannizzaro reaction serves for preparation of both acids and alcohols, each normally in 50% yield. As example, the preparation of 2-furoic acid and fur-furyl alcohol from 2-furaldehyde is here recorded.499... 

Solution A characteristic reaction of aldehydes withouta-hydrogens is the oxidation-reduction they undergo in the presence of a strong base. This is the Cannizzaro reaction. It involves the attack of a hydroxyl ion upon the aldehyde s carbonyl carbon, followed by a hydride shift to give a carboxyl group. A possible mechanism is illustrated below. 

Aldehydes that have no a hydrogen undergo an intermolecular oxidation—reduction called the Cannizzaro reaction when they are treated with concentrated base. An example is the following reaction of benzaldehyde ... 

Base-Catalyzed Oxidation-Reduction of Aldehydes by the Cannizzaro Reaction... 

Purpose To demonstrate the oxidation-reduction of an aromatic aldehyde to give the corresponding alcohol and carboxylic acid salt by the Cannizzaro reaction. 

The Cannizzaro reaction is an oxidation-reduction sequence. What type of reagent is formaldehyde acting as in... 

Scheme 9.4. The Caimizzaro reaction. The oxidation-reduction of benzenecarbaldehyde (benzaldehyde) to benzenecarboxylic acid (benzoic acid) and phenylmethanol (benzyl alcohol). Note the transfer of a hydride (H ) ion from one carbon to another, accounts for the oxidation (hydrogen, H, loss), and reduction (hydrogen, H , gain). (See Cannizzaro, S. Liebigs Ann. Chem., 1853,88, 129.)...

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