Properties of Various Groups as Relevant to the MCAT

Group	Elimination reactions	Addition reactions	Substitution reactions	Acidity/ Basicity	Solubilty in water*
C-H	�	�	Free radical; electrophilic aromatic if part of benzene ring	Generally neutral	Poor
Carbon-carbon double bond C=C	�	Electrophilic	�	Generally neutral	Poor
Hydroxyl -OH	Dehydration	�	Nucleophilic	Very weak acid	Good
Carbonyl C=O	�	Nucleophilic (e.g. aldol condensation)	�	Very weak acid a -H acidic � carbanion	Good
Carboxylic acid -COOH	�	�	Nucleophilic (can form esters, acid chlorides, anhydrides, amides, keto acids)	Weak acid	Good
-Halide	�	�	Nucleophilic	Generally neutral	Poor
Benzene	�	�	Electrophilic aromatic	Generally neutral	Poor
Ether C-O-C	�	�	The acid cleavage of ethers involves a nucleophilic substitution	Very weak base	Good
Phenol	�	�	-H attached to benzene ring: Electrophilic aromatic	Weak acid	Good
Amine - NH2	�	�	Amine acts as a nucleophile in SN2 reaction with acid chloride to form an amide; similar reaction with alkyl halides to form alkylamines	Weak base	Good

* Generally, a compound is water-soluble if it has only one to three carbon atoms and a hydrophilic group, especially one that can form hydrogen bonds with water molecules.