All right. So this first one would be no reaction. We know that because we said that the second molecule can't be oxidized at all. So there's no point in even drawing a product. Now carbon right here has only one bond to another carbon. So that means if it has one bond to carbon, how many oxygens can it possibly have? 3. So what that means is that I need to draw a version of this carbon that's going to have 3 bonds to oxygen. If you looked at our intro to redox chart where I talk about things that are getting oxidized and things that are getting reduced, the version of carbon with 3 oxygens would be a carboxylic acid. So what I would do is I would draw that carbon with a double bond O and with an OH. What that's going to do is now that's going to keep my carbon-carbon bond, so I'm not breaking the rule. I'm not breaking that bond. But now I have 1, 2, 3 bonds to oxygen. All right. Cool.
So now how about this last one? Well, this last one, I'll move out of the way so you guys can see it. This last one you will find is that that carbon once again only had one bond to carbon, but it already had 1, 2 bonds to oxygen. So how many extra bonds to oxygen could it have? Well, we already know that the rule says you can only have 4 bonds and one of them has to be to carbon. That means that the last third bond could also be an oxygen. So what I'm going to do here is I'm going to try to move out of the way here. I'm going to draw this molecule once again also as a carboxylic acid. Why? Because basically, when you're oxidizing something with 2 bonds to oxygen, you want it to look like a ketone, and then when we have one bond to oxygen, you want it to look like an alcohol, which is the one that I have up there. Okay. Good. Awesome.
So now what I want to do is I want to show you guys another reagent. It turns out that even though we deal with strong oxidizing agents a lot, there's also a reagent that's called a weak oxidizing agent. Now a weak oxidizing agent would simply be one that doesn't oxidize multiple times. The way that we're going to define it in particular is that it can only add one equivalent of oxygen to primary alcohols. That's really the only difference. So what that means is that it's going to do the same thing as all the other reagents, KMnO4, chromium 6, same thing, except in one situation. In a primary alcohol, instead of going all the way to a carboxylic acid, it's going to go one equivalent instead of 2 equivalents of oxygen. So let me show you what that looks like. Pcc is the name of this reagent and it is our weak oxidizing agent. So would it be able to oxidize my secondary alcohol? Absolutely. It's going to do the same exact thing. So for PCC, I would get the same exact reagent here or the same exact product. Would it be able to oxidize number 2? No. Nothing can oxidize number 2. It's still no reaction. Would it be able to oxidize number 3? Yes, it would. But this is our special situation. Notice that I have a primary alcohol. Whenever you have a primary alcohol, what that means is that for a strong oxidizing agent, I would have taken it to a carboxylic acid like this. But for a weak oxidizing agent like PCC, I'm going to go to an aldehyde instead. So that means that I'm actually going to draw this thing like this with an H instead of an OH. That's the biggest difference here. That's actually the only major difference that we have with PCC is that instead of getting carboxylic acid, we get an aldehyde.
Now you might be wondering, what do you mean by one equivalent of oxygen? All I mean is that notice that at the beginning how many bonds to oxygen did we have? We had 1. I'm just going to say 1 O. At the end of the strong oxidation, how many did we have bonds to oxygen? We had 3. 3 O. So that means that if we had 1 oxygen to begin with and 3 to end with, we added 2 equivalents of oxygen. Well, for PCC, instead of using doing 2 equivalents of oxygen, now we're only going to add one equivalent because now we have 2 bonds to O instead of 1, which is what it started with. So if you're starting with 1 and you're with 2, that means you only added one equivalent of oxygen and that's what this definition has to do with. But if you want to remember, just say that primary alcohols go to aldehydes. That's another way of saying it. That's maybe less complicated and that's always right. You could just say it like that the rest of your life if you want to and that's fine. Let's get down to our last structure. Would it be able to oxidize my 4? And the answer is no. This would be no reaction. Why is that? Well, because it's already an aldehyde. Notice that aldehyde is the product of PCC. PCC is going to make an aldehyde. So if we have an aldehyde already, is it going to do anything to it? No. Okay. So once it's in aldehyde, it's not going to oxidize it more. This would be no reaction as well. Okay. So just trying to show you guys the difference between PCC and the other oxidizing agents. It's not that hard. It's just a few details you have to keep in mind. All right. So that said, let's go ahead and move on.
