Skip to main content
Ch. 18 - Ketones and Aldehydes
Wade - Organic Chemistry 9th Edition
Wade9th EditionOrganic ChemistryISBN: 9780135213728Not the one you use?Change textbook
Chapter 18, Problem 16b

Show how you would accomplish the following syntheses.
b. cyclopentanecarbaldehyde → 2-cyclopentyl-2-hydroxyacetic acid

Verified step by step guidance
1
Step 1: Begin by identifying the functional groups in the starting material (cyclopentanecarbaldehyde) and the target molecule (2-cyclopentyl-2-hydroxyacetic acid). Cyclopentanecarbaldehyde contains an aldehyde group (-CHO), while the target molecule contains a hydroxyl group (-OH) and a carboxylic acid group (-COOH) attached to the same carbon.
Step 2: Plan the transformation of the aldehyde group into a carboxylic acid group. This can be achieved through oxidation. Use an oxidizing agent such as potassium permanganate (KMnO₄) or chromium-based reagents like Jones reagent (CrO₃/H₂SO₄) to convert the aldehyde (-CHO) to a carboxylic acid (-COOH).
Step 3: Introduce the hydroxyl group (-OH) at the alpha-carbon of the carboxylic acid. This can be accomplished through an aldol reaction or a hydroxylation step. For example, you can use a base like NaOH to generate an enolate intermediate, followed by reaction with an appropriate electrophile to add the hydroxyl group.
Step 4: Ensure stereochemistry is correct for the hydroxyl group addition. If stereoselectivity is required, consider using reagents or conditions that favor the desired stereochemical outcome, such as chiral catalysts or specific reaction temperatures.
Step 5: Purify the product (2-cyclopentyl-2-hydroxyacetic acid) using techniques like recrystallization or chromatography to ensure the final compound is free of impurities and matches the desired structure.

Verified video answer for a similar problem:

This video solution was recommended by our tutors as helpful for the problem above.
Video duration:
6m
Was this helpful?

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Functional Groups

Functional groups are specific groups of atoms within molecules that are responsible for the characteristic chemical reactions of those molecules. In this synthesis, understanding the aldehyde functional group in cyclopentanecarbaldehyde and the hydroxyl and carboxylic acid groups in 2-cyclopentyl-2-hydroxyacetic acid is crucial for determining the necessary reactions and reagents.
Recommended video:
Guided course
02:36
Identifying Functional Groups

Synthesis Pathways

Synthesis pathways refer to the step-by-step methods used to convert one compound into another through chemical reactions. For the transformation from cyclopentanecarbaldehyde to 2-cyclopentyl-2-hydroxyacetic acid, identifying the appropriate reactions, such as reduction and functional group transformations, is essential to achieve the desired product efficiently.
Recommended video:
2:13
Energy Production In Biochemical Pathways Concept 1

Reagents and Reaction Conditions

Reagents are substances used to cause a chemical reaction, while reaction conditions include factors like temperature, pressure, and solvent choice that influence the reaction's outcome. Knowing which reagents to use, such as reducing agents or catalysts, and the optimal conditions for each step in the synthesis is vital for successfully converting cyclopentanecarbaldehyde into the target compound.
Recommended video: