Guide to Studying Reactions
What should you know about each reaction?
Name? General and sometimes specific.
What are the reactants?
Are there any special limitations? (acidity,basicity; 1°, 2°, 3° functional group)
What are the reagents and solvents?
Know what the acronyms stand for.
What are the products?
Is it Regiospecific?
Is it Stereospecific?
What is the mechanism?
Be able to write it.
Know the supporting evidence?
How does this reaction compare with others?
Do others have a similar mechanism?
Do others yield the same product? From the same or different starting materials?
Example
Name: Electrophilic Addition of alkenes - Hydrohalogenation
Reactants: any alkene
Reagents: HX - any hydrogen halide (HF, HCl, HBr, HI); done under acidic conditions
Products: alkyl halides
Regiospecific - Markovnikov addition
No pattern of stereospecificity is observed
Mechanism: polar reaction
electrophilic attack on C=C
H
+
:X-
+
X
H
+ X-
X
Rearrangement sometimes occurs suggesting carbocations; products are consistant with
more stable carbocation intermediate
Same as most electrophilic additions. One atom attaches to each end of the double bond consistant
with Markovnikov's rule. The electrophilic atom (H +) attaches first and ends up in the less
substituted position followed by the nucleophile (X -)at the more substituted position.
Halogenation of alkanes yields similar products but not with the same specificity (lower yield of
desired product) and by a different mechanism.