Question

Give the systematic IUPAC name for each of the following alcohols: (a) \(\mathrm{CH}_{3}-\mathrm{CH}_{2}-\mathrm{CH}_{2}-\mathrm{CH}_{2}-\mathrm{OH}\) (b) \(\mathrm{CH}_{3}-\mathrm{CH}_{2}-\mathrm{CH}(\mathrm{OH})-\mathrm{CH}_{3}\) (c) \(\mathrm{CH}_{2}(\mathrm{OH})-\mathrm{CH}_{2}-\mathrm{CH}_{2}-\mathrm{CH}_{3}\) (d) \(\mathrm{CH}_{3}-\mathrm{CH}(\mathrm{OH})-\mathrm{CH}_{2}-\mathrm{CH}_{3}\)

Short answer

(a) Butan-1-ol, (b) Butan-2-ol, (c) Butan-1-ol, (d) Butan-2-ol.

Step-by-step solution

Identify the Longest Carbon Chain for Each Alcohol

To determine the IUPAC name for each alcohol, begin by identifying the longest continuous carbon chain that includes the alcohol group (-OH). The chain length determines the root name: propane (3 carbons), butane (4 carbons), etc.

Number the Carbon Chain

Number the longest carbon chain such that the carbon with the -OH group has the lowest possible number. Start numbering from the end nearest to the -OH group.

Identify the Alcohol's Position

Based on your numbering, determine the position of the -OH group. Include this position number before the root name to indicate exactly where the alcohol group is located on the chain.

Determine the Name of Each Alcohol

For each compound, add the suffix '-ol' to the root name. Don’t forget to include the position number of the -OH group. Here are the names for each part: - (a) The longest chain is 4 carbons, the -OH is on the 1st carbon: Butan-1-ol. - (b) Four carbons with the -OH on the 2nd: Butan-2-ol. - (c) Four carbons with the -OH on the 1st: Butan-1-ol. - (d) Again four carbons with the -OH on the 2nd: Butan-2-ol.

Key concepts

Understanding Organic Chemistry

Organic chemistry is the branch of chemistry that explores the structures, properties, and reactions of organic compounds and materials. These compounds contain carbon atoms, typically bonded to hydrogen, oxygen, nitrogen, and other elements.

Organic chemistry is essential in understanding the composition of many of the things that make up life and materials around us, from fuels and plastics to pharmaceuticals and food. A fundamental concept in organic chemistry is the study of hydrocarbons, which can form straight chains, branched chains, or ring structures. This versatility is one reason why carbon is the backbone of organic chemistry.

In this context, understanding how to structure and name these compounds systematically is crucial for communication and further study in this field.

All About Alcohols

Alcohols are a category of organic compounds characterized by the presence of one or more hydroxyl (-OH) groups attached to a carbon atom. These hydroxyl groups are what distinguish alcohols from other types of organic molecules.

Alcohols can vary in the complexity and number of hydroxyl groups they contain, leading to a wide range of physical and chemical properties. Commonly known alcohols include ethanol, which is found in alcoholic beverages, and methanol, which is used as an industrial solvent. Alcohols are classified by the number of hydroxyl groups and the nature of the carbon to which they are attached, such as primary, secondary, or tertiary alcohols.

• Primary Alcohols: The -OH group is connected to a carbon atom that is attached to only one other carbon atom.
• Secondary Alcohols: The -OH group is connected to a carbon atom that is attached to two other carbon atoms.
• Tertiary Alcohols: The -OH group is connected to a carbon atom that is attached to three other carbon atoms.

Versatility in alcohols' structural possibilities underscores their importance in the realm of chemistry.

Systematic Naming in Organic Chemistry

Systematic naming, or IUPAC nomenclature, is a standardized method for naming chemical compounds. This naming system allows chemists across the world to communicate more effectively by having a unique name for each compound based on its structure.

When it comes to naming alcohols, the IUPAC system is straightforward but requires attention to detail. The steps involved include identifying the longest carbon chain containing the alcohol group and numbering the chain to give the lowest possible number to the -OH group. The name of the compound is then constructed by noting the position of the hydroxyl group and adding the suffix '-ol' to the root name of the carbon chain.

• Identify the longest carbon chain that includes the -OH group; this determines the base name (e.g., propanol, butanol).
• Number the chain such that the -OH group gets the lowest number.
• State the position of the -OH group before the base name (e.g., Butan-1-ol for a four-carbon chain with -OH on the first carbon).
• Add the '-ol' suffix to indicate the presence of an -OH group.

Using systematic nomenclature aids in clarity and consistency, vital for learning and advancing in organic chemistry.