Synthesis of Aldehydes and Ketones

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. All reactions are given for a sample ketone; examples for aldehydes are only given where the reaction is different.

By Oxidation


Other reagents: K2Cr2O7 + H2SO4 or CrO3 + H2SO4 or KMnO4 + OH- or KMnO4 + H3O+
McMurry 17.8, 19.2, 19.3, Fessenden 7.8C, 13.2, Schmid 11.18

Note that all aqueous chromium reagents and permanganate oxidize primary aldehydes to carboxylic acids and cannot be used for this reaction; selective reagents are needed.
McMurry 17.8, 19.2, 19.3, 20.6, Fessenden 7.8C, 13.2, Schmid 11.18
  2
McMurry 7.8, 19.2, Fessenden 10.13B, Schmid 14.5

Other reagents: CrO3 + HOAc and several other chromium reagents.
McMurry 19.2, 19.3, 19.10, 20.6, Fessenden 13.7, Schmid 20.9B

By Reduction


Note that Grignard reagents reduce ketones to tertiary alcohols and cannot be used for this reaction; selective reagents are needed.
McMurry 19.2, 19.8, 21.8, Fessenden 15.3C, Schmid 16.14B

Note that LiAlH4 and NaBH4 reduce aldehydes and ketones to alcohols and cannot be used for this reaction; selective reagents are needed.
McMurry 21.4, Fessenden 15.3C, Schmid 16.14A

By addition


McMurry 8.5, Fessenden 10.7, Schmid 9.7A

McMurry 8.5, Fessenden 10.9 Schmid 9.7B

By Substitution

+
Mechanism!
McMurry 16.4, Fessenden 11.8E, 15.3C, Schmid 21.9
+ 2 CH3CH2OH
+
Ketones and aldehydes are easily regenerated from their acetals, imines, enamines, etc. Since water has replaced something else, the process is called hydrolysis.
Mechanism! Reversible
McMurry 19.9, 19.11Fessenden 13.4B, 13.5B, Schmid 14.11, 14.13
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Last update Feb 10, 1999