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Example Questions
Example Question #1 : Other Reaction Mechanisms
2-butene reacts with (dibromine in a tetrachloromethane solvent). What is the final product?
No reaction
Here we have a classic electrophilic addition reaction.
We must remember that a double bond is an area in a molecule that has a high electron density. As a result, double bonds can act as nucleophiles and react with good electrophiles.
In this problem, the alkene attacks the dibromide to form a bromonium ion, which is rather unstable. The bromonium ion pulls carbon's electrons toward itself, causing the carbons in the bromonium complex to have a slightly negative charge. As a result, the negatively charged bromine can attack either of the carbon atoms and, thus, we have added two bromines to our carbon chain.
Example Question #1 : Help With Electron Pushing
How many stable resonance structures are there for the following molecule (include the given structure in your total count)?
3
6
4
5
1
5
The five resonance structures of the given molecule are shown below:
Example Question #2 : Help With Electron Pushing
Rank the following compounds in order of increasing rate of electrophilic aromatic substitution.
II, IV, III, I, V
IV, V, I, III, II
II, I, III, IV, V
V, I, III, IV, II
V, II, I, III, IV
V, I, III, IV, II
The nitro substituent is strongly deactivating, ketones are moderately deactivating substituent, halides are weakly deactivating, alkyl groups are weakly activating, and amine groups are strongly activating.