Carboxylic acids degradation with loss

Trifluoroacetic acid sodium nitrite trifiuoroacetic anhydride Nitriles from carboxylic acids Degradation with loss of 1 C-atom... 

Hofmann degradation of carboxylic acid amides with loss of 1 G-atom s. 17, 337... 

Carboxylic from ethylenecarboxylic acids Degradation with loss of 2 C-atoms Yarrentrapp reaction... 

Racemic or achiral a-azido acids are synthesized by direct azide substitution on commercially available a-bromo carboxylic acids or by radical bromination of carboxylic acids followed by azide substitution. In general, azido acids are stored in the dark to avoid photolytic degradation with loss of nitrogen temperatures above 50 °C should be avoided. Radical a-bromination of a-branched carboxylic acids as required for the synthesis of a,a-dialkyl or a,a-diaryl amino acids is performed with A-bromosuccinimide. This is followed by nucleophilic substitution with sodium azide or other azide donors, e.g. tetrabutylannmonium azide, to produce achiral or racemic a-azido-a,a-diaIkyl or a-azido-a,a-diaryl carboxylic acids (Scheme 74).Synthesis of more sterically hindered a,a-disubstituted azido acids leads to hydroxy compounds when prolonged reaction times are required and not sufficient care is taken to operate under dry conditions and an inert atmosphere.t ... 

Ethylene derivs. from carboxylic acids via imidazole N- C-acyl group migration and Norrish type II cleavage Degradation with loss of 2 C-atoms... 

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