General, Organic, and Biological Chemistry Copyright © 2010 Pearson Education, Inc.1 Chapter 14 Aldehydes, Ketones, and Chiral Molecules 14.3 Oxidation and Reduction of Aldehydes and Ketones

General, Organic, and Biological Chemistry Copyright © 2010 Pearson Education, Inc.2 Oxidation  Aldehydes are easily oxidized to carboxylic acids.

General, Organic, and Biological Chemistry Copyright © 2010 Pearson Education, Inc.3 Tollens’ Test  Tollens’ reagent, which contains Ag +, oxidizes aldehydes but not ketones.  Ag + is reduced to metallic Ag, which appears as a “mirror” in the test tube.

General, Organic, and Biological Chemistry Copyright © 2010 Pearson Education, Inc.4 Benedict’s Test In the Benedict’s test,  Cu 2+ reacts with aldehydes that have an adjacent —OH group  aldehydes are oxidized to carboxylic acids  Cu 2+ is reduced to give Cu 2 O(s)

General, Organic, and Biological Chemistry Copyright © 2010 Pearson Education, Inc.5 Learning Check Write the condensed structural formula and the name of the oxidized product when each of the following is mixed with Tollens’ reagent: A. Butanal B. Acetaldehyde C. Ethyl methyl ketone

General, Organic, and Biological Chemistry Copyright © 2010 Pearson Education, Inc.6 Solution A. Butanal B. Acetaldehyde C. Ethyl methyl ketone None. Ketones are not oxidized by Tollen’s reagent. Butanoic acid Ethanoic acid, acetic acid