MCAT Organic Chemistry Review 2018-2019

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groups that act as good nucleophiles, electrophiles, or leaving groups? This step will help define a
category of reactions that can occur with the given functional groups.


Step 3: Identify the Other Reagents


In this step, determine the properties of the other reagents in the reaction. Are they acidic or basic?
Are they suggestive of a particular reaction? Are they good nucleophiles or a specific solvent? Are
they good oxidizing or reducing agents?


Step 4: Identify the Most Reactive Functional Group(s)


Once you’ve identified the functional groups in the compound and the other reagents present, this
step should be relatively quick. Remember that more oxidized carbons tend to be more reactive to
both nucleophile–electrophile reactions and oxidation–reduction reactions. Note the presence of
protecting groups that exist to prevent a particular functional group from reacting.


Step 5: Identify the First Step of the Reaction


If the reaction involves an acid or a base, the first step will usually be protonation or deprotonation.
If the reaction involves a nucleophile, the first step is generally for the nucleophile to attack the
electrophile, forming a bond with it. If the reaction involves an oxidizing or reducing agent, the most
oxidized functional group will be oxidized or reduced, accordingly.


Once you know what will react, think through how the reaction will go. Did the protonation or
deprotonation of a functional group increase its reactivity? When the nucleophile attacks, how does
the carbon respond to avoid having five bonds? Does a leaving group leave, or does a double bond
get reduced to a single bond (like the opening of a carbonyl)?


Step 6: Consider Stereospecificity/ Stereoselectivity


Though not all reactions are stereospecific or stereoselective, these possibilities should be
considered when predicting products. For stereospecificity, consider whether the configuration of
the reactant necessarily leads to a specific configuration in the product, as seen in SN2 reactions.
Stereoselectivity, on the other hand, occurs in reactions where one configuration of product is more
readily formed due to product characteristics. Stereoselectivity is seen in many reactions, as

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