in Figure 8.17. The enol that is initially formed from the destruction of the ring tautomerizes to the
more stable keto form.
Figure 8.17. Decarboxylation of Carboxylic Acids: Loss of CO 2
The intramolecular reaction proceeds via a six-membered ring transition state, and the product
tautomerizes from the enol to the more stable keto form.BRIDGE
Decarboxylation is common in biochemical pathways in the body. Pyruvate dehydrogenase
complex, described in Chapter 10 of MCAT Biochemistry Review, carries out the
decarboxylation of pyruvate to help form acetyl-CoA, which can feed into the citric acid
cycle.SAPONIFICATION
When long-chain carboxylic acids react with sodium or potassium hydroxide, a salt is formed. This
process, called saponification, occurs by mixing fatty acids with lye (sodium or potassium
hydroxide), resulting in the formation of a salt that we know as soap. Soaps can solvate nonpolar
organic compounds in aqueous solutions because they contain both a nonpolar tail and a polar
carboxylate head, as shown in Figure 8.18.