No reaction gives at least one ketone as a significant organic product except for the oxidation of secondary alcohols.

Oxidation of Primary Alcohols:
- Primary alcohols can be oxidized to produce aldehydes or carboxylic acids.
- In the presence of a strong oxidizing agent like potassium permanganate (KMnO4) or potassium dichromate (K2Cr2O7), primary alcohols are converted into carboxylic acids.
- The reaction involves the loss of two hydrogen atoms from the alcohol, resulting in the formation of a carboxylic acid.
- No ketone is formed in this process.

Oxidation of Tertiary Alcohols:
- Tertiary alcohols cannot be oxidized under normal conditions.
- They lack the hydrogen atom attached to the carbon atom bearing the hydroxyl group, which is necessary for oxidation.
- Therefore, no ketone or other oxidation product is formed.

Oxidation of Secondary Alcohols:
- Secondary alcohols can be oxidized to produce ketones.
- The oxidation reaction involves the loss of one hydrogen atom from the alcohol, resulting in the formation of a ketone.
- Common oxidizing agents for this reaction include chromic acid (H2CrO4) or pyridinium chlorochromate (PCC).
- The reaction proceeds through the formation of a carbonyl intermediate, which is then further oxidized to the ketone.
- Therefore, the oxidation of secondary alcohols is the only reaction that gives at least one ketone as a significant organic product.

In summary, while primary alcohols can be oxidized to form aldehydes or carboxylic acids, and tertiary alcohols cannot be oxidized, the oxidation of secondary alcohols is the only reaction that leads to the formation of ketones.