Cinnamaldehyde, Perkin reaction

Cinnamaldehyde (39), which is a vinylog of benzaldehyde, gives excellent yields of p-styrylacrylic acid (40) under Perkin reaction conditions3 or Knoevenagel conditions.9... 

Under the usual conditions of the Perkin reaction, cinnamaldehyde gives an excellent yield of 5-phenyl-2,4-pentadienoic acid 890 but decarboxylation occurs when it is heated with phenylacetic acid and acetic anhydride in the presence of lead(n) oxide, 1,4-diphenyl-1,3-butadiene being formed in 30% yield,891 and under these conditions two equivalents of cinnamaldehyde and one of succinic acid give l,8-diphenyl-l,3,5,7-octatetraene.892... 

Diphenylocta-1,3,5,7-tetraene can be prepared (Expt 6.140) by condensing two mols of cinnamaldehyde with succinic acid in the presence of acetic anhydride and lead oxide, in a reaction which bears similarities with those of the Perkin type discussed above. 

Thiele and Schleussner prepared ira/ii,franj-l,4-diphenylbutadiene by reaction of cinnamaldehyde with sodium phenylacetate and acetic anhydride at a temperature such that the initially formed product of Perkin condensation loses carbon dioxide. Kuhn and Winterstein employed lead oxide as the base and reported an increase in crude yield from 20 to 34%. The lower yield of 23-25% reported in Organic... 

In 1868 W. H. Perkin, Sen., discovered that heating the sodium derivative of salicylaldehyde with acetic anhydride led to coumarin,882 and this reaction has gained great importance as a method of synthesizing <%,/ -unsaturated acids. The method consists of heating an aromatic aldehyde with the anhydride of an aliphatic acid and the sodium or potassium salt of the same acid. This reaction, the Perkin synthesis, can also be carried out with cinnamaldehyde but not with purely aliphatic aldehydes. 

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