# What is Wrong with this name? (hint-draw the molecule out first) 3-butene

Jun 1, 2018

The correct IUPAC name is but-1-ene.

#### Explanation:

The structure of the compound would be

You started numbering from the wrong end.

You must number the carbon atoms from the end closest to the double bond.

The $\text{C=C}$ is then between carbons 1 and 2.

The PIN (Preferred IUPAC Name) is but-1-ene.

A name like 1-butene is acceptable, but the PIN puts the locant as close to its functional group as possible.