Ketone Nomenclature

Concept: Concept: Nomenclature

Video Transcript

Hey guys! Let’s learn how to name ketones. Ketones are going to modify the root name of a carbon chain. You’re going to take out the e ending of the carbon courage chain and then you’re replace it with the suffix -one. I know that looks like one. Please do not say one. It’s pronounced -one like ketone.
In this video, we're not going to discuss the prioritization of all functional groups in terms of numbering locations but just suffice it to say that ketones are going to have higher priority than pretty much all the groups you learned in Orgo 1, including alcohols. If you saw an alcohol and a ketone next to each other, and you had to figure out which one gets the higher priority with naming and numbering, you would pick the ketone.
There’s IUPAC name and there’s common names. When you're assigning common names to ketones, then you’re going to name both of the R-groups alphabetically here and you’re going to end with the word ketone.
Let me just show you a really quick example of the difference between common and IUPAC. Let’s say you have a four-carbon chain with a carbonyl in the middle. In IUPAC, the name of this would be, it starts off as a butane, now it's going to be a butanone and you have to name the location because I need to know exactly where that ketone is. It could be anywhere. I’m going to name this as a 2-butanone. That would be IUPAC.
In terms of common naming, it would be a little different. For the common name, you would just name the substituents in alphabetical order and end with the word ketone. Then it would be on ethyl methyl ketone, almost like it’s an ether. Remember that ethers you can do that as well. You can name both of the substituents and end with ether. This would be an ethyl methyl ketone.
This common naming system is actually pretty common with a lot of ketones that you’ll find in the lab because in the lab, we work with a lot of smaller ketones. But once you get to larger and more complex ketones that have bigger branching group, the common naming system just becomes impossible to use because now you’re going to have to name these huge bulky substituents in common names and it just gets terrible. You should use IUPAC. Definitely use IUPAC for more complex ketones. It’s okay to use common names for the easier to name ones, the smaller ketones.
We’re going to do two examples. I know you guys got this. Let’s start off with the first one. Obviously I don't need the common name for this. I just want the IUPAC name, so go for it.