Question

Which of the following IUPAC names indicates Homocyclic compound? (A) Cyclohexane- 1,2 -dicarboxylic acid (B) Cyclohexane- 1,2 -dicarboxylic anhydride (C) Benzene carbonyl chloride (D) Cyclopent-3-en-1-ol

Short answer

Both (A) Cyclohexane-1,2-dicarboxylic acid and (D) Cyclopent-3-en-1-ol are homocyclic compounds, as their cyclic rings consist only of carbon atoms.

Step-by-step solution

(A) Cyclohexane-1,2-dicarboxylic acid

This compound is a cyclohexane ring with two carboxyl (COOH) groups at positions 1 and 2. Since the cyclic ring consists only of carbon atoms, this compound is homocyclic.

(B) Cyclohexane-1,2-dicarboxylic anhydride

This compound is formed by removing a water molecule from two carboxylic acid groups in cyclohexane-1,2-dicarboxylic acid. The cyclic ring still consists of only carbon atoms, so this compound is also homocyclic.

(C) Benzene carbonyl chloride

This compound is a benzene ring with a carbonyl group (C=O) and a chloride group (Cl) attached to it. Although benzene is a homocyclic compound, the presence of the carbonyl group and the chloride group makes this compound heterocyclic, and therefore it is not a homocyclic compound.

(D) Cyclopent-3-en-1-ol

This compound consists of a cyclopentene ring, which means it has 5 carbon atoms and one double bond in the ring. It also has an alcohol group (OH) attached to carbon 1. The cyclic ring only has carbon atoms, so this compound is homocyclic. Conclusion: Both (A) Cyclohexane-1,2-dicarboxylic acid and (D) Cyclopent-3-en-1-ol are homocyclic compounds, as their cyclic rings consist only of carbon atoms.

Key concepts

IUPAC Nomenclature

The International Union of Pure and Applied Chemistry (IUPAC) nomenclature is a standardized system used for naming chemical compounds. This helps chemists and scientists worldwide understand the structure and details of a compound from its name, without needing to see its chemical formula or structure.
The IUPAC naming system follows certain rules:

• The longest continuous chain of carbon atoms forms the base name of the compound.
• Functional groups are identified and indicated with a suffix or prefix in the name.
• Numbers are used to specify the position of substituents on the carbon chain.
• For cyclic compounds, 'cyclo-' is used before the base name to signify that the structure is a ring.

Understanding these rules can help in deciphering names like 'Cyclohexane-1,2-dicarboxylic acid', where 'cyclohexane' indicates a six-carbon ring and 'dicarboxylic acid' signifies the presence of two carboxyl groups. Numbering helps determine their positions. This methodical approach ensures clarity and precision in naming compounds.

Cyclohexane Derivatives

Cyclohexane derivatives are compounds that originate from cyclohexane, which is a simple, saturated carbon ring consisting of six carbon atoms. Derivatives of cyclohexane are formed by replacing one or more hydrogen atoms with other atoms or functional groups.
These modifications lead to a wide variety of cyclohexane-based compounds:

• Adding functional groups such as hydroxyl (OH), carboxyl (COOH), or halogens (F, Cl, Br, I) alters the chemical and physical properties of cyclohexane.
• Cyclohexane-1,2-dicarboxylic acid, for example, has two carboxyl groups replacing hydrogen atoms, making it a dicarboxylic acid.
• Modifications can affect the compound's reactivity, boiling and melting points, and solubility.

Understanding these derivatives allows better insights into their practical applications and roles in various chemical reactions.

Organic Chemistry

Organic chemistry involves the study of carbon-based compounds, which can also include other elements such as hydrogen, oxygen, nitrogen, and halogens. This branch of chemistry is crucial because it encompasses a vast number of compounds found in nature and synthetic materials.
Organic compounds are broadly classified based on their structure and the presence of functional groups. Functional groups play a significant role in dictating a compound's chemical behavior. Cyclohexane, being a homocyclic compound with only carbon in its ring, fits into this category.
Organic chemistry helps us understand how these compounds interact, their synthesis, and their applications. For instance:

• Knowledge of organic chemistry guides the creation of pharmaceuticals, plastics, and petrochemicals.
• It enables the modification of compounds to enhance their desired properties or reduce undesirable ones.
• Reactivity trends, where the stability and transformations of organic molecules are studied, are explored here.

Mastering organic chemistry is pivotal in the development and manipulation of materials to meet human needs.