Varrentrapp reaction

Alkali fusion of oleic acid at about 350°C ia the Varrentrapp reaction causes double-bond isomerization to a conjugated system with the carboxylate group followed by oxidative cleavage to form palmitic acid (75). In contrast, alkaU fusion of riciaoleic acid is the commercial route to sebacic acid [111 -20-6] ... 

Varrentrapp reaction. Cleavage of oleic acid into palmitic and acetic acids by heating with molten potassium hydroxide. The procedure has been extended to olefinic acids in general. 

Degradation with loss of 2 C-atoms—Varrentrapp reaction s. 16, 293... 

In the Varrentrapp reaction certain unsaturated fatty acids are cleaved in molten alkali, a reaction at one time of relevance to structure elucidation. 

The movement of double bonds in long-chain unsaturated acids has been known since Varrentrapp converted oleic acid to palmitic by fusion with alkali, an observation which led to the invalid conclusion that oleic acid was the A2 or A3 acid. Double bond migration unaccompanied by chain fission occurs under milder conditions. The reaction also occurs more easily with methylene-interrupted polyene acids to give products with conjugated unsaturation which are easily recognized by ultraviolet spectroscopy (Section 9.3). 

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