Reactions of Ketones and Aldehydes

You may use these summaries and problems but you may NOT download them for use at another site, nor may you charge for access to them. Copyright Linda M. Sweeting 1997

The following example reactions are organized by type, with references to text chapters. Links within these summaries (which may show up as boxes around reagents) will provide further information about the reagents and their other reactions. Return to Graphical Reaction Summary menu for other functional group choices. Most reactions are given for a sample ketone; reactions which are different for aldehydes are labelled so.

Reversible Addition to the Carbonyl


Mechanism! Reversible, with equilibrium favoring C=O
McMurry 19.11, Fessenden 13.4A, Schmid 14.10

Mechanism! Reversible
McMurry 19.11, Fessenden 13.4B, Schmid 14.11

Mechanism!
McMurry 19.7, 20.6, Fessenden 13.4C, Schmid 14.9

Irreversible Addition: Reduction


Other reagents: NaBH4, H2, Pt
McMurry 17.5, 19.8, Fessenden 13.6B, Schmid 11.7

McMurry 17.6,19.8, Fessenden 13.4D, Schmid 11.7

Clemmensen reduction
Other reagents: NH2NH2 + KOH (Wolff-Kischner) or ethanethiol in acid, followed by Raney nickel. If the aldehyde or ketone in conjugated with an aromatic ring, e.g. benzaldehyde, complete reduction can be done with H2, Pd (McMurry 16.11)
Fessenden 13.6C, Schmid 21.10

Addition + Elimination = Substitution

+
An imine
Mechanism!
McMurry 21.7, Fessenden 13.5A, Schmid 14.13 - 14.15
+
An enamine, which reacts like an enolate
McMurry19.9, Fessenden 13.5B, Schmid 14.13, 17.14

Wittig Reaction (also a reduction); see halide reactions for synthesis of the reagent.
McMurry 19.12, Fessenden 13.5D, Schmid 14.16 - 14.17

Oxidation (Aldehydes only)


Tollens' test
Other reagents: Ag2O, Cu++ (Fehling's and Benedict's tests), all aqueous Cr(VI) reagents, KMnO4
McMurry 17.8, 19.2, 20.6 Fessenden 13.7, Schmid 14.18
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Last update Feb, 10, 1999