Molecules with the ketone functional group will have the suffix -one. For instance, in
This would be 2-pentanone. You must number ketones, unlike aldehydes, since the ketone
will not be located at the end of a carbon chain. Like always, you try to get the lowest
In terms of functional group priority, ketones take priority over everything but
carboxylic groups and aldehydes. So, among all the functional groups that are no located
at the end, ketones have highest priority.
If an aldehyde or carboxylic functional group is presenta long with the ketone, the
ketone becomes an oxo- prefix. So, in the case of this molecule: