Question

Draw a structural formula for each of the following: a. methyl butanoate b. ethyl acetate c. \(o\) -chlorobenzoic acid d. 2,2 -dimethyl- 3 -chloro-butanoic acid

Short answer

The structural formulas for the given compounds are as follows: a. Methyl butanoate: CH3-O-C(O)-CH2-CH2-CH3 b. Ethyl acetate: CH3-CH2-O-C(O)-CH3 c. \(o\)-chlorobenzoic acid: \(\mathrm{\begin{array}{c} Cl \\[-2.5ex] {} - \textbf{C}_6\textbf{H}_5\textbf{-C}(O)\textbf{OH} \end{array}}\) d. 2,2-dimethyl-3-chloro-butanoic acid: CH3-C(CH3)2-CH(Cl)-C(O)OH

Step-by-step solution

a. Methyl butanoate

Methyl butanoate is an ester, which consists of a carbonyl group (C=O) and an alkyl group (R) bound to the oxygen atom. To draw a structural formula for methyl butanoate, break down the name: 1. Methyl: CH3 group 2. Butanoate: O-C(O) and the rest of the molecule which is a butane (four carbons) chain The structural formula for methyl butanoate is: CH3-O-C(O)-CH2-CH2-CH3.

b. Ethyl acetate

Ethyl acetate is also an ester. To draw the structural formula for ethyl acetate, break down the name: 1. Ethyl: CH3-CH2 group 2. Acetate: O-C(O) and the rest of the molecule which is a methane (one carbon) chain The structural formula for ethyl acetate is: CH3-CH2-O-C(O)-CH3.

c. \(o\)-chlorobenzoic acid

\(o\)-chlorobenzoic acid is an aromatic halide with a carboxylic acid group. The "\(o\)" refers to the ortho-position, which means that the halogen atom (chlorine) is located at the carbon atom adjacent to the carboxylic acid group. The benzoic acid portion consists of a benzene ring with a carboxylic acid group attached to one of the carbon atoms. Thus, the structural formula for \(o\)-chlorobenzoic acid is: \( \mathrm{ \begin{array}{c} Cl \\[-2.5ex] {} - \textbf{C}_6\textbf{H}_5\textbf{-C}(O)\textbf{OH} \end{array} } \)

d. 2,2-dimethyl-3-chloro-butanoic acid

2,2-dimethyl-3-chloro-butanoic acid is a carboxylic acid with additional methyl and halide groups. To draw the structural formula for this compound, follow these steps: 1. Butanoic acid: Start with the butanoic acid molecule (C(O)OH), which contains a four-carbon chain and a carboxylic acid group at one end 2. 2,2-dimethyl: Add two methyl groups (CH3) at the second carbon of the chain 3. 3-chloro: Add a chlorine atom at the third carbon of the chain The structural formula for 2,2-dimethyl-3-chloro-butanoic acid is: CH3-C(CH3)2-CH(Cl)-C(O)OH.

Key concepts

Methyl Butanoate

Methyl butanoate is a fascinating ester, which is a type of organic compound that combines a carbonyl group (C=O) with an alkyl group linked to an oxygen atom. To understand its structure, let's break down its components:

• Methyl Group (CH₃): This is the part of the molecule that contributes the alkyl group attached to the oxygen atom of the ester linkage.
• Butanoate: This is derived from butanoic acid and forms the backbone of the ester. "Butanoate" indicates a four-carbon chain.

The complete structural formula for methyl butanoate is represented as: CH₃-O-C(O)-CH₂-CH₂-CH₃. Here, the CH₃ group, or methyl group, is bonded through an oxygen atom to the carbon skeleton. Such arrangements give esters their distinctive fruity smells.

Ethyl Acetate

Ethyl acetate, like methyl butanoate, is another ester but with its own unique properties and usages. It is often utilized as a solvent due to its ability to dissolve a wide range of compounds. Breaking down ethyl acetate helps illustrate its structure:

• Ethyl Group (CH₃-CH₂): This two-carbon chain is the "ethyl" part of the molecule.
• Acetate: Derived from acetic acid, it contains one carbon attached to the ester.

The structural formula for ethyl acetate is: CH₃-CH₂-O-C(O)-CH₃. The ethyl group connects to the acetate part through an oxygen atom. This simple but effective bond creates a molecule highly valuable in industries from perfumes to coatings.

Ortho-Chlorobenzoic Acid

Ortho-chlorobenzoic acid showcases how simple nomenclature can reveal the structural secrets of a chemical compound. It falls under aromatic compounds due to its constituent benzene ring. Let's delve into its structure:

• Benzene Ring: A classic aromatic structure providing a stable platform for attachments.
• Ortho Position: This refers to substituents (first being chlorine) that are directly adjacent to the carboxylic group on the benzene ring.
• Carboxylic Acid Group (-COOH): Provides acidic characteristics to the compound.

The structural formula is represented with a benzene ring having a chlorine atom and a carboxylic acid group on neighboring carbon atoms, as in: \[\mathrm{ \begin{array}{c} Cl \ {} - \textbf{C}_6\textbf{H}_5\textbf{-C}(O)\textbf{OH} \end{array}}\]The ortho location of chlorine gives it distinct reactivity patterns compared to meta or para isomers.

Dimethyl-3-Chloro-Butanoic Acid

This compound, 2,2-dimethyl-3-chloro-butanoic acid, might sound complex, but once broken down, its structure becomes clear.

• Butanoic Acid Base: It provides the four-carbon chain ending with a carboxylic acid group (-COOH).
• 2,2-Dimethyl Substitution: Two methyl groups attached to the second carbon in the chain create significant steric hindrance.
• 3-Chloro: A chlorine atom placed on the third carbon adds notable chemical characteristics.

The resulting structural formula is: CH₃-C(CH₃)₂-CH(Cl)-C(O)OH. These branches and substitutions affect both the physical and chemical properties of the molecule, including boiling point and reactivity. Understanding the placement of these groups helps predict how the molecule will behave in different chemical environments.