Question

MCAT Tutorial: Carboxylic Acids

Answer 1

\({\bf{Basic~Definition}}\) a compound with the carboxyl functional group



Nomenclature: replace the "e" suffix with -oic acid. The carbon in the carboxyl functional group is typically given priority 1 in naming.

\({\bf{Properties}}\)
- hydrogen bonding
- higher BP's
- can exist as cyclic dimers between carboxyl groups
- high acidity (upon deprotonation of the hydroxyl, forms stable carboxylate anion)

Answer 2

Aromatic Carboxylic Acids: made more acidic by deactivating groups and less acidic by activating (electron donating) groups



Reactions w/ Bases: produce carboxylate salts. Can be purified by reacting w/ basic solution to form salt, then re-acidify the salt.

beta-dicarboxylic acids (1,3 dicarboxylic acids): the hydrogens between the two groups can be abstracted to produce a stabilized anion and thus a strong acid.

Answer 3

\({\bf{Synthesis:}}\)
1. oxidize alcohols or aldehydes
2. cleave alkenes/alkynes

Nitrile Hydrolysis: converts alkyl halides into carboxylic acids via SN2

Answer 4

Grignard Reaction:

Answer 5

\({\bf{Reactions:}}\)

Reduction using LiAlH4 or BH3

Answer 6

Decarboxylation (1,3 dicarbonyl compounds)

Answer 7

Fischer Esterification: react carboxylic acid with alcohol and acid catalyst. Only works for simple esters (4 carbon chain or less)

HVZ reaction: brominate the alpha carbon by reacting with Br2, PBr3, H2O

Answer 8

Anyway, that's the end of my tutorial, I hope it was a helpful resource. Source material is the 2nd Edition Barron's Prep book for the new MCAT