Question

Give the IUPAC and common names (if any) for each of the following compounds: a. CC(C)CCC(=O)O b. CCOC(=O)c1ccccc1 C. CCCC(=O)OCC d. O=C(O)c1ccccc1Cl CCCCC(=O)O E.

Short answer

a. 2-Methylpentanoic acid (no common name) b-nEthyl benzoate (no common name) c. Ethyl butanoate (no common name) d. 4-Chlorobenzoic acid (no common name) e. Pentanoic acid (Valeric acid)

Step-by-step solution

Identify the Functional Groups

First, identify the functional groups in each compound provided by the SMILES notation. For example, examine 'CC(C)CCC(=O)O' to find the carboxyl group, 'COC(=O)c1ccccc1' to find the ester group, etc.

Determine the Longest Carbon Chain Including the Functional Group

Find the longest continuous chain of carbon atoms that includes the functional group for each compound. For compound a, 'CC(C)CCC(=O)O', the chain has six carbons with a carboxyl group at the end, making it a derivative of hexanoic acid.

Number the Carbon Chain

Number the carbon chain starting from the end nearest to the highest priority functional group. For compound b, 'CCOC(=O)c1ccccc1', the ester group has the highest priority and we begin numbering from the ester oxygen.

Name the Main Chain and Add Substituents

Name the main chain based on the total number of carbons and their functional group. Add any substituents as prefixes in alphabetical order. For example, compound c, 'CCCC(=O)OCC' is named by finding the longest chain including the ester, resulting in ethyl butanoate.

Review the Compound for Common Names

Verify if any common names exist for the compounds. For example, 'CCCCC(=O)O' has the IUPAC name of pentanoic acid and the common name of valeric acid.

Key concepts

Functional Groups

Understanding functional groups is essential in naming organic compounds. Functional groups are specific groups of atoms within molecules that are responsible for the characteristic chemical reactions of those molecules. Here are some common functional groups you might encounter:

• Carboxyl group (-COOH), found in carboxylic acids
• Ester group (-COOR), found in esters
• Hydroxyl group (-OH), found in alcohols
• Amino group (-NH2), found in amines

These groups alter the properties of the molecule and give us clues on how to name the compound. For example, in the compound 'CC(C)CCC(=O)O', the ‘(=O)O’ part indicates a carboxyl group. Realizing this helps us understand the molecule belongs to the carboxylic acids family.

Carbon Chain

The carbon chain is the backbone of organic molecules. When naming molecules, identifying the longest continuous chain of carbon atoms is crucial. This chain forms the base name of the compound. For instance, 'CC(C)CCC(=O)O' has a chain of six carbon atoms, making 'hexane' the base name before adding the functional group's designation.
Here are steps to correctly identify the longest chain:

• Look for the longest continuous sequence of carbons.
• Ensure the chosen chain includes the functional group.
• If multiple chains of the same length are found, choose the one with the highest number of substituents.

Identifying the main carbon chain helps in systematically naming organic compounds.

Prioritizing Substituents

Prioritizing substituents is key to correctly naming organic molecules. Substituents are atoms or groups of atoms attached to the main carbon chain. The rules are as follows:

• Number the carbon chain starting from the end nearest the highest priority functional group.
• Functional groups are ranked by their reactivity and influence on the molecule’s properties.
• If there is a tie in substituent positions, use the alphabetical order to decide.

For instance, in 'CCCC(=O)OCC', the ester group gets priority in numbering, starting from the carbon attached to the oxygen of the ester. This systematic prioritization ensures that the nomenclature is consistent and clear, following IUPAC guidelines.