2.4.6- Trimethylmandelic acid

Mesitoic acid has been prepared by carbonation of mesityl-magnesium bromide 2-4 by hydrolysis of its amide prepared by condensation of mesitylene with carbamyl chloride under the influence of aluminum chloride 6 by oxidation of isodurene with dilute nitric acid 6-7 by distillation of 2,4,6-trimethylmandelic acid (low yield) 8 by dry distillation of 2,4,6-trimethyIphenyl-glyoxylic acid 9 by oxidation of the latter with potassium permanganate 10 and by treating 2,4,6-trimethylphenylglyoxylic acid with concentrated sulfuric acid in the cold11 or with heating.12... 

Mesitoic acid has been obtained by hydrolysis of its amide which was prepared from mesitylene, carbamyl chloride, and aluminum chloride in carbon disulfide.1 It has been prepared by heating isodurene with dilute nitric acid,2,3 in small yields by the distillation of 2,4,6,-trimethylmandelic acid,4 by dry dis-... 

Mesitylacetic acid has been prepared from 2,4,6-trimethyl-acetophenone by treatment with yellow ammonium sulfide and hydrolyzing the resulting amide with alkali,6 by the dry distillation of 2,4,6-trimethylmandelic acid,7 by heating 2,4,6-trimethyl-phenylglyoxylic acid with hydriodic acid and red phosphorus,8 and by treating mesitylacetonitrile with potassium hydroxide.4... 

The released end-group forms an a-dicarbonyl structure which rearranges by an intramolecular, Cannizzaro type of reaction to yield saccharinates. Intramolecular reactions of the Cannizzaro type can occur not only with dialdehydes but also with a-ketoaldehydes and a-diketones ( benzilic acid rearrangement ) they can be exemplified by the base-catalyzed rearrangement of phenylglyoxal (VIII) [or of (2,4,6-trimethylphenyl)-glyoxal ] to the salt of mandelic acid (IX) (or of 2,4,6-trimethylmandelic acid). 

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