Answer to Question #179691 in Organic Chemistry for soph

Question

1. Using at least 1 orbital overlap diagram, explain why benzene undergoes substitution reactions instead of 3 addition reactions.
2. In your own words, explain what is meant by “functional groups” and why alkyl groups aren’t considered functional.
3. Show the condensation reaction between pentanedioic acid and ethane-1,2-diol to form a polyester.
4. Draw the protein strand below as a structural diagram.  Highlight the peptide linkages.

Answer 1

1.

There are delocalised electrons above and below the plane of the ring. The presence of the delocalised electrons makes benzene particularly stable. Benzene resists addition reactions because that would involve breaking the delocalisation and losing that stability.

2. A functional group is a specific group of atoms or bonds within a compound that is responsible for the characteristic chemical reactions of that compound. The same functional group will behave in a similar fashion, by undergoing similar reactions, regardless of the compound of which it is a part.

Alkyl groups are not functional groups because alkyl chains are often nonreactive, and the direction of site-specific reactions is difficult; unsaturated alkyl chains with the presence of functional groups allow for higher reactivity and specificity. Often, compounds are functionalized with specific groups for a specific chemical reaction.

3.

+

=

4. Incomplete question, n