Trans -Cinnamic acid

The effect of polar groups on the diimide reaction is sensitive to the configuration of the attached groups. For example, fumaric acid (trans) is ten times as reactive as maleic acid (els ) and the ratio of reactivities of the geometrical isomers of cinnamic acid, trans/cis. is 10 3 (ref. 21b). In comparison, cis- and trans-2-butene have almost identical reactivities. The difference may be explained by a change in the degree of advancement of the transition state towards the saturated product where the eclipsed conformation would result in a greater non-bonded repulsive interaction between the cis-substituents than the trans. 

The elimination of alcohols 13A to give cinnamic acids trans-13B in aqueous sulfuric acid has been studied, If optically active 13A is used and the reaction stopped at 10% completion, the starting material is found to be completely racemized. What can you deduce about the mechanism of the elimination step ... 

The boll weevil antifeedants, anthranilic acid, gentisic acid, senecioic acid, trans-cinnamic acid, trans-cinnamaldehyde and camphor have been Isolated from the Peruvian plant Alchornea triplinervia (Euphorbiaceae). Anthranilic acid and camphor also showed significant Inhibition of growth of the tobacco budworm. 

Hjelte showed that a,/3-unsaturated acids can be reduced by hydrazine and Raney nickel in an alkaline medium. Thus a solution of cinnamic acid (trans) in slightly more than I equivalent of aqueous sodium hydroxide was treated with a small amount of W-6 Raney nickel, and 2 moles of hydrazine was added with agitation at 90° during 2 hrs. 

Cinnamic acid (trans) CfiHs CH CH COOH monoclinic 1.25... 

Cinnamic acid, (E)- (E)-Cinnamic acid. See trans-Cinnamic acid trans-Cinnamic acid... 

Cinnamal C9H8O2 Cinnamic acid trans-Cinnamic acid Dihydrocoumarin 1 -Phenyl-1,2-propanedione C9H8O3... 

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