How do aldehydes and ketones differ from alcohol?

1 Answer
Sep 7, 2016

An alternative means of differentiation is to consider the degree of oxidation of the ipso carbon.

Explanation:

Aldehydes and ketones are the oxidation products of alcohols, and we could assign formal oxdation states.

The oxidation state of the ipso carbon in H_3C-CH_2OHH3CCH2OH is -II; in H_3C-C(=O)HH3CC(=O)H, +I+I, and in H_3C-C(=O)OHH3CC(=O)OH, +III+III. Of course +III+III represents its maximum oxidation state (CO_2CO2 can be formed, but here the chain is broken).

By comparison, we could assign the formal oxidation numbers of carbon in say propane or butane: H_3stackrel(""^(-)III)C-stackrel(""^(-)II)CH_2CH_3H3IIICIICH2CH3, or H_3stackrel(""^(-)III)C-stackrel(""^(-)II)CH_2stackrel(""^(-)II)CH_2CH_3H3IIICIICH2IICH2CH3

Certainly we use oxidizing agents to synthesize ketones and aldehydes from alcohols.