Question

The organic compound formed by the dry distillation of calcium adipate is reduced with zinc amalgam and concentrated hydrochloric acid. The final product formed is (a) cyclopentane (b) pentane (c) cyclopentanol (d) cyclohexane

Short answer

Answer: The final product obtained in the given organic chemistry problem is cyclopentane.

Step-by-step solution

Identify the organic compound formed by the dry distillation of calcium adipate

Calcium adipate has the formula (Ca(CH2)4(COO)2). Dry distillation of calcium adipate leads to the formation of cyclopentanone with calcium carbonate and water as by-products. The reaction can be represented as follows: Ca(CH2)4(COO)2 → C5H8O + CaCO3 + H2O

Determine the structure of cyclopentanone

Cyclopentanone has the molecular formula C5H8O. It is a cyclic ketone with a five-membered ring. The structure of cyclopentanone is: ``` O ╲╝ ─── / \ │ │ \ / ─── ```

Understand the reaction with zinc amalgam and concentrated hydrochloric acid

The reaction of cyclopentanone with zinc amalgam (Zn-Hg) and concentrated hydrochloric acid (HCl) is a reduction reaction. This reaction is known as Clemmensen reduction, which is used to convert ketones into alkanes by replacing the carbonyl group (C=O) with an H2 group.

Find the final product and match it with the given options

As we perform Clemmensen reduction on cyclopentanone, the carbonyl group (C=O) is replaced with an H2 group. This results in the formation of cyclopentane, which is an alkane with a five-membered ring. The final product can be represented as follows: ``` ─── / \ │ │ \ / ─── ``` Comparing this final product with the given options, we find that the correct option is (a) cyclopentane.

Key concepts

Cyclopentanone

Cyclopentanone is an important organic compound in the field of chemistry. It has the molecular formula \( C_5H_8O \). In its structure, it consists of a five-membered carbon ring with a ketone group. This means there is a carbon-oxygen double bond present in the ring.
This compound is classified as a cyclic ketone, and the circular structure significantly affects its chemical properties, making it reactive compared to non-cyclic ketones. Cyclopentanone serves as a building block for various organic synthesis processes. It's often used in the manufacturing of perfumes, pharmaceuticals, and other organic compounds.

Calcium Adipate Distillation

Calcium adipate distillation is a method to produce cyclopentanone from calcium adipate. Calcium adipate, with the formula \( Ca(CH_2)_4(COO)_2 \), undergoes decomposition when heat is applied in a dry distillation process.

• This reaction yields cyclopentanone as the main organic product.
• Calcium carbonate \( (CaCO_3) \) and water \( (H_2O) \) are by-products of this reaction.

Dry distillation is often used in organic chemistry to decompose materials by heat in the absence of oxygen. This method helps to isolate specific products useful for further reactions or applications.

Organic Reactions

Organic reactions are chemical processes involving organic compounds. These reactions are vast and diverse, encompassing everything from basic families like alkanes to complex biomolecules. Some fundamental types of organic reactions include:

• Substitution reactions, where atom(s) in a molecule are replaced by other atom(s).
• Addition reactions, where atoms are added to a molecule without the loss of other atoms.
• Elimination reactions, which involve the removal of elements to form double or triple bonds.
• Redox reactions, where reduction and oxidation occur.

Understanding these reactions is essential for applications in fields like pharmaceuticals, petrochemicals, and material science.

Zinc Amalgam Reduction

Zinc amalgam reduction, also known as Clemmensen reduction, is a notable organic reaction. This process involves the reduction of ketones to alkanes using zinc amalgam (a mixture of zinc and mercury) and concentrated hydrochloric acid.
The Clemmensen reduction is particularly useful for converting the carbonyl group \((C=O)\) in ketones and aldehydes into a simple \( -CH_2- \) group. This removal of the oxygen atom simplifies the molecule and is vital in synthesizing certain hydrocarbons. In the context of cyclopentanone, zinc amalgam reduction transforms it into cyclopentane, an inert hydrocarbon with significant stability.