Question

Draw the condensed structural formula of each of the following: a. pentyl formate b. 2,3 -dichlorobutanoic acid c. 3,5 -dimethylhexanoic acid d. butyl propanoate

Short answer

a. HCOOCH2CH2CH2CH2CH3b. ClCH2CH(Cl)CH2COOHc. CH3 CH2CH(CH3)CH2CH(CH3)COOHd. CH3CH2COOCH2CH2CH2CH3

Step-by-step solution

Understand the naming of the compounds

Each name follows IUPAC nomenclature rules. Identify the root name, functional groups, and substituents for each compound.

Draw the condensed structural formula for pentyl formate

Pentyl formate consists of a pentyl group (5-carbon chain, C5H11) attached to a formate group (HCOO). Condensed structural formula: **HCOOCH2CH2CH2CH2CH3**

Draw the condensed structural formula for 2,3-dichlorobutanoic acid

2,3-Dichlorobutanoic acid has a 4-carbon chain (C4H7), with two chlorine atoms on the second and third carbons, and a carboxylic acid group at the end: **ClCH2CH(Cl)CH2COOH**

Draw the condensed structural formula for 3,5-dimethylhexanoic acid

3,5-Dimethylhexanoic acid includes a 6-carbon chain (C6H11), with methyl groups on third and fifth carbons, and a carboxylic acid group: **CH3CH2CH(CH3)CH2CH(CH3)COOH**

Draw the condensed structural formula for butyl propanoate

Butyl propanoate involves a butyl group (4-carbon chain, C4H9) attached to a propanoate group (C2H5COO): **CH3CH2COOCH2CH2CH2CH3**

Key concepts

IUPAC nomenclature

The IUPAC nomenclature is a systematic way of naming chemical compounds, established by the International Union of Pure and Applied Chemistry (IUPAC). This method ensures uniformity and clarity in the naming of chemical substances.
For organic compounds, the name usually comprises three parts:

• The root name that indicates the longest continuous carbon chain
• The suffix which describes the primary functional group
• The prefixes representing substituents and their positions on the chain

For example, in 2,3-dichlorobutanoic acid, 'butan-' signifies a four-carbon chain, 'oic acid' indicates the presence of a carboxylic acid group, and '2,3-dichloro' shows that there are chlorine atoms attached to the second and third carbon atoms in the chain.

Organic Chemistry

Organic chemistry is the branch of chemistry that studies carbon-containing compounds. These compounds often contain hydrogen, oxygen, nitrogen, and other elements.
Organic chemistry is essential because it deals with the substances that make up all living organisms. The subject covers a wide range of compounds, including hydrocarbons, alcohols, acids, esters, and many more.
The structure, properties, and reactions of these compounds are studied to understand their behavior and applications in fields like medicine, agriculture, and industry.

Functional Groups

Functional groups are specific groups of atoms within molecules that have characteristic properties and reactivities. They play a central role in organic chemistry as they determine the behavior of the entire molecule in chemical reactions.
Some common functional groups include:

• Hydroxyl (–OH) in alcohols
• Carbonyl (–C=O) in ketones and aldehydes
• Carboxyl (–COOH) in carboxylic acids
• Ester (–COO–) in esters

Understanding these functional groups helps predict how organic compounds will react under various conditions. They are also critical in classifying and naming organic molecules according to IUPAC rules.

Carboxylic Acids

Carboxylic acids are a group of organic compounds characterized by the presence of a carboxyl group (–COOH). This group consists of a carbonyl (C=O) and a hydroxyl (–OH) group bonded to the same carbon atom.
Carboxylic acids are named using the IUPAC system by replacing the ending of the parent alkane name with '-oic acid'. For instance, a four-carbon acid is called 'butanoic acid'.
Some properties of carboxylic acids include:

• They are typically weak acids
• They have higher boiling points than alcohols or aldehydes
• They are often soluble in water and can form hydrogen bonds

Examples in the exercise include 2,3-dichlorobutanoic acid and 3,5-dimethylhexanoic acid.

Esters

Esters are derived from carboxylic acids and alcohols. They contain the functional group –COO–, where one oxygen is bonded to a carbon atom, and the other oxygen is bonded to another carbon atom.
In nomenclature, esters are named by considering the alcohol and acid from which they are derived. The alkyl group from the alcohol gets listed first, followed by the acid part with '-oate' replacing '-ic acid'.
For example, butyl propanoate derives from butanol and propanoic acid. The condensed structural formula shows the arrangement of atoms succinctly, such as **CH3CH2COOCH2CH2CH2CH3**.
Esters are known for their pleasant fragrances and are used in flavors and perfumes.