Molecular rearrangement, degradation

Hofmann degradation of benzamide This reaction produces aniline, which contains one less carbon than the starting material (benzamide). The group (phenyl) attached to the carbonyl carbon in the amide (benzamide) is found joined to nitrogen in the product (aniline). This is an example of molecular rearrangement. 

The peroxyl radicals M-0-0 thus formed undergo a variety of molecular rearrangements and/or elimination reactions until the final oxidation products are formed. In reality, these oxidation products are interfering with hydroxyl radical attack on M and hence they are complicating the product spectrum considerably. Additionally, the bicarbonate and carbonate radicals may introduce selective oxidation reactions into the degradation cycle (Fig. 6-16). 

Thomson, T., Stevens, T. S. Degradation of quaternary ammonium salts. V. Molecular rearrangements in related sulfur compounds. J. Chem. Soc., Abstracts 1932, 69-73. 

This means the synthesis must employ a reaction that generates an amine of 1 less carbon from succinic anhydride. Such a reaction is the Hofmann degradation of amides. As seen below, the reaction involves the migration of a group from carbonyl carbon to the adjacent nitrogen atom. It is therefore an example of a molecular rearrangement. ... 

Alkali ne Degradation. This method of analysis of polysaccharides provides little information about overall structure of polysaccharides due to the complex nature of the reactions involved which includes isomerization, oxidation, reduction, molecular rearrangements of reducing residues and the fragmentation of polysaccharide chains. 

Thermal degradation reactions of polymers can be divided into two broad groups molecular rearrangement reactions and reactions which involve ho-mol5d ic scission of bonds to produce free radicals. In both cases the chemistry... 

As well as naturally resistant starch complexes, there are different types of modified starches that are manufactured by the food industry for a variety of reasons. They can be defined as native starches that have been submitted to one or more physical, chemical, or enzymatic treatments promoting granular disorganization, polymer degradation, molecular rearrangements, oxidation, or chemical group... 

McNeill and Rincon studied thermal degradation of PC by means of TGA, TVA, DSC, FT-IR, mass spectrometry (MS) and gas chromatogra-phy-MS (GC-MS) method (see Fig. 2.5). PC is stable up to 300°C. Above that temperature, small quantities of phenol and p-cresol were detected, at 375-400°C CO2 appeared and then at T > 455°C CO and CH4 were formed the peak on the DTG curve was at F = 462°C. At 500°C the main products are q chc dimer and bisphenol A, with small quantities of CO2, p-cresol, p-ethyl phenol, phenol, p-vinyl phenol, p-isopropyl phenol, CO and CH4. In the absence of air and moisture, degradation of PC proceeds by hemolytic decomposition of the polymer chain, radical reactions, fragmentations and molecular rearrangements. 

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