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Chapter Contents
- 24.1 The Carbonyl Group
- 24.2 Naming Aldehydes and Ketones
- 24.3 Physical and Chemical Properties of Aldehydes and Ketones
- 24.4 Some Common Aldehydes and Ketones
- Summary
- Review
In this chapter, you will learn about
- The carbonyl functional group, and the structures of aldehydes and ketones
- Naming aldehdyes and ketones
- Physical and chemical properties of aldehydes and ketones
- Common aldehydes and ketones
To better support your learning, you should be familiar with the following concepts before starting this chapter:
- sp2–sp2 hybridization, sigma and pi bonding to form double bonds in organic molecules
- General nomenclature rules for naming alkanes
- The difference between a physical and a chemical property of matter
Aside from carbon, which is found in all organic compounds, one of the most common atoms found in organic molecules is oxygen. When carbon double bonds with an oxygen atom, this grouping of atoms (termed a “carbonyl group”) is very reactive and is the functional group that is always found in both aldehydes and ketones. The Formica tabletops that are found at most diners, the adhesives that are used to manufacture the plywood used to make your shed, and the formaldehyde used to preserve animal specimens in a science lab are all examples of common aldehydes. Similarly, the main component of most nail polish removers, acetone, is one of the simplest and most common ketones that we encounter regularly. But aldehydes and ketones are not all harsh chemicals – many spices and flavouring agents that we eat daily belong to these two groups of organic molecules. Cinnamon, vanilla, and the characteristic flavour of almonds are all due to the presence of aldehyde molecules. And that butter flavour in your microwave popcorn, or the distinctive flavour of blue cheese? These are due to the presence of ketones.
From a biochemistry standpoint, aldehydes and ketones are essential to life on Earth. Carbohydrates exist as aldehydes and ketones: the special reactivity of aldehydes and ketones allow starches and cellulose to form long polymers, which allow both plants and animals to store energy long-term. DNA, which is the genetic code for all living things on this planet, is bonded in place by carbonyl group chemical reactions: the genetic code of adenine, guanine, cytosine, and thymine is connected to a “backbone” which is provided by the carbonyl group.
Spotlight: Aroma Chemistry: The smell of wet dog
Attribution & References
Except where otherwise noted, this page is adapted by Gregory A. Anderson from “15: Aldehydes and Ketones” In Map: Fundamentals of General Organic and Biological Chemistry (McMurry et al.)by LibreTexts, licensed under CC BY-NC-SA 3.0 .
Attribution from original source:
- 16.5: Other Oxygen-Containing Functional Groups In Beginning Chemistry (v. 1.0) by Anonymous is licensed CC BY-NC-SA 3.0.
