Anhydride Nomenclature

Concept: Concept: Anhydride Nomenclature

Video Transcript

Now we're going to learn how to name anhydrides. Anhydride are a specific functional group that come up a lot in this section. They’re one that you might not be very familiar with at all. Let’s just back up for a second to talk about what is an anhydride.
Basically, an anhydride is a carboxylic acid derivative. Think of it as a carboxylate but then you've got an acyl group on the other side, then you've got your carbonyl and R. Another way to think of it is that it’s a dicarbonyl with an O in the middle, whatever you want to think. In terms of naming, the naming of it is going to be visualized in this manner. Basically when you look at an anhydride, it's actually kind of a combination of two carboxylic acids. You could say that maybe this was carboxylic acid 1 and maybe this was carboxylic acid 2, and maybe they came together and made an anhydride. Side note, that’s actually how you make anhydrides. You make anhydrides by combining to carboxylic acids into an anhydride. That's where the name stems from.
What we do is it’s really easy. You just alphabetize your two different acids, visualize them with the carbon chains. But then instead of ending with the word acid, you would end with the word anhydride. Another special situation is what happens if your R groups are the same? What happens if both sides of my anhydride are symmetrical? Then you don't have to say that it's carboxylic acid 1, carboxylic acid 2. Anhydride, you could just say carboxylic acid 1 anhydride. It’s just alkynoic anhydride. Why? Because that means that you're assuming that one combined with another version itself to make an anhydride. You're basically saying that this is the anhydride you would yield through the condensation of these two carboxylic acids.
Let me see. That’s obviously just going really I don't want to mess up any questions for you. But this anhydride, I could name it as both the common and the IUPAC. Let’s start off with IUPAC. For IUPAC, this would be ethanoic here and this is propanoic. For IUPAC, it’s going to be ethanoic, propanoic anhydride, not acid. Don’t make that mistake. Common. The common is going to be acetic and propionic. These are the ones you’re supposed to memorize. Again, alphabetical order. We're going to get acetic propionic anhydride. Now you see why it's so important to know those first five for the common names because they can come up with all of these derivatives. That's it. Move on to the question. Let’s see if you can get it right and then I'll give you the answer. 

Concept: Example 1: Provide the IUPAC name for the molecule