Problem 12 - Chemistry in 30 days

Question

The IUPAC name of(a) 3 -hydroxycyclohexene (b) cyclohexen-3-ol (c) cyclohex-2-en-1-ol (d) 2 -ene-cyclohexan-1-ol

Step-by-Step Solution

Answer

The correct IUPAC name is (c) cyclohex-2-en-1-ol.

Step 1: Analyze the Structure of the Compound

Firstly, identify each provided name and construct the chemical structure in your mind or on paper to simplify understanding. This visualization helps in cross-monitoring the possible structure with its IUPAC name.

Step 2: Compare Each Option

Carefully compare the provided names, looking at the positions of the alcohol group (-OH) and the position of the double bond within the cyclohexene ring.

Step 3: Identify Correct IUPAC Naming

For IUPAC naming, ensure that the numbering of the ring prioritizes the lowest possible numbers for the substituents and functional groups, as well as the double bond. This means the double bond's position should be numbered first when possible.

Step 4: Select the Correct IUPAC Format

Based on the rules of IUPAC naming, the correct format should have numbers indicating the positions of the functional groups and double bonds, followed by the name, hence forming a systematic order.

Step 5: Verify Final Answer

Once you have the understanding and selected format, write the name in the IUPAC standardized form: Cyclohex-2-en-1-ol takes priority and conforms to the given rules accurately within option (c).

Key Concepts

Organic Chemistry

Organic chemistry centers around the study of carbon-containing compounds and their various structures, properties, and reactions. Atoms of carbon have the unique ability to form stable bonds with other carbon atoms, leading to an impressive diversity of complex molecules. This field is crucial for understanding how molecules interact within biological systems, as well as in synthesizing new materials for industry and technology. Organic chemistry includes a vast array of compounds, from simple hydrocarbons to complex polymers and biologically active compounds.

Functional Groups

Functional groups are specific groups of atoms within molecules that are responsible for the chemical properties of the compound. They play a pivotal role in organic chemistry, offering a way to classify and predict the behavior of organic molecules.

• Common functional groups include hydroxyl groups (-OH), carbonyl groups (C=O), carboxyl groups (-COOH), and amino groups (-NH₂).
• Functional groups determine reactivity, solubility, and boiling/melting points of organic compounds.

In the exercise, the hydroxyl group that combines with the cyclohexene ring forms a part of the compound used to determine its IUPAC name.

Cyclohexene

Cyclohexene is a simple cyclic alkene characterized by a ring of six carbon atoms with a single double bond. As a hydrocarbon, it consists only of carbon and hydrogen.

• The presence of the double bond makes cyclohexene more reactive than its alkane counterpart, cyclohexane.
• Its cyclic structure forces the carbon chain to adopt particular conformations, impacting its chemical properties and reactions.

In nomenclature, the position of such features is crucial to provide accurate and systematic IUPAC names for compounds such as cyclohex-2-en-1-ol.

Double Bond Position

The position of a double bond in a compound is a key factor in its IUPAC naming and chemical behavior. In the context of cyclohexene, the position of the double bond affects the numbering of the carbon ring and, by extension, the position of functional groups like hydroxyl groups.

• When naming compounds, the carbon atoms are numbered in a way that gives the smallest possible numbers to the double bond and functional groups.
• This principle ensures clarity and consistency in the naming across different compounds.

In the exercise, the correct naming involves giving priority to the double bond in numbering, resulting in the name cyclohex-2-en-1-ol, which indicates the double bond starts at the second carbon of the ring. This precise method of identifying the position is a fundamental aspect of IUPAC nomenclature.