Classification Of Organic Compounds

A heterocyclic compound is a compound that contains atoms of at least two different elements as members of its ring structure. In the case of heterocyclic compounds, the heteroatom is usually an element such as nitrogen, oxygen, or sulfur. - Pyridine is a heterocyclic compound because it contains a six-membered ring with one nitrogen atom replacing a carbon atom in the ring. This nitrogen atom is the heteroatom in pyridine. - Benzene, Toluene, and Cyclohexane are not heterocyclic compounds. Benzene and toluene are aromatic compounds with only carbon and hydrogen atoms, while cyclohexane is a saturated hydrocarbon with only carbon and hydrogen atoms. Thus, Pyridine is the heterocyclic compound.

Step 1: Understanding the Concept:
IUPAC naming: Select the longest carbon chain containing the principal functional group (ketone here). Number to give the principal group the lowest number.

Step 2: Detailed Explanation:
Structure: HO-CH -CH -CH -CH -CH -CO-CH .
Total carbons: 7 (heptane). Principal group: ketone (one at C2). Hydroxy group (-OH) at C7.
Numbering from the end closer to the ketone: CH -CO- is C1-C2? No — ketone gets lower number: CO is at C2, so CH is C1. Then chain extends to OH at C7.
Name: 7-Hydroxyheptan-2-one.

Step 3: Final Answer:
The IUPAC name is 7-Hydroxyheptan-2-one.

Step 1: Understanding the Concept:
A heterocyclic aromatic compound is a cyclic compound containing atoms of at least two different elements in its ring, and it follows Huckel's rule for aromaticity.

Step 2: Detailed Explanation:
Analyze each option:
• Phenol, Aniline, Toluene, Naphthalene: These are all aromatic but their rings consist only of carbon atoms. They are carbocyclic, not heterocyclic.
• Pyridine: It has a six-membered aromatic ring containing one nitrogen atom. It is a classic example of a heterocyclic aromatic compound.

Step 3: Final Answer:
Pyridine is a heterocyclic aromatic compound.