What is the IUPAC name of a compound that has four carbon atoms and ends with a ketone?

The IUPAC naming convention for organic compounds follows specific rules. In this case, the compound has four carbon atoms and contains a ketone functional group.

To identify the correct name, we first need to determine the structure of the compound. A ketone is characterized by the carbonyl group (C=O) that is bonded to two carbon atoms. In a four-carbon ketone, the carbonyl group can be positioned at either the first or the second carbon atom.

However, when naming ketones, the numbering of the carbon chain begins at the end closest to the carbonyl carbon. If the carbonyl group is on the second carbon, the appropriate name incorporates the prefix for the number of carbon atoms ("butan-" for four carbons) along with the suffix that denotes its functional group, which for ketones is "-one." Therefore, the correct structure for a four-carbon ketone with the carbonyl group on the second carbon is butan-2-one.

In conclusion, "butan-2-one" accurately reflects both the number of carbons and the position of the ketone functional group within the compound.