Provide the necessary reagents for the following transformatio...

Question

Provide the necessary reagents for the following transformation.

Chemical reaction showing oxidation of alcohols to aldehydes and ketones.

Accepted Answer

Hey guys. Let's take a look at the following practice question. Here it says, provide the necessary reagents for the following transformation. If we take a look at this, what we have initially is a ketone. What we're doing here is we're changing this ketone into an ester. Remember, an ester is a carbonyl connected to O connected to C. So this portion makes it the ester. Remember, a ketone is a carbonyl with a carbon on either side. Now, there are a couple of ways that we can change a ketone into a ester. An ester. In this case, what we can do here is we can do the Baer Villiger reaction, Baer Villiger reaction. Now, remember the Baer Villiger reaction uses a peroxyacid to change a ketone into an ester. So, ketones normally don't get oxidized. This is one of the rare exceptions where we can. So here, we use a peroxyacid. Remember, peroxyacid is RCO3H. It's kind of like a carboxylic acid except it has one additional oxygen. Instead of being Cl2H, it's Cl3H. We'll say here that the most common one that we know of is mcpba which looks like this. We're going to say mcpba stands for meta, which remember means 13 because they are 13 apart. Chloro because of the chlorine. Peroxy and remember the peroxyacid portion is this portion. Peroxybenzoic because of the benzene acid. It's like a carboxylic acid so it's enzoic acid just like a carboxylic acid would. Now, here, remember the Baer Villiger reaction follows what we call a migratory aptitude. Basically, the migratory aptitude means the groups that are more likely to leave the carbonyl carbon so that oxygen can come in its place. So the migratory aptitude is H would move out of the way first, then a tertiary carbon, then a secondary carbon which is equal to a phenyl carbon, and phenyl means benzene, Then a primary carbon and finally a methyl carbon will be the last to move out of the way. So if we take a look here, what's going to happen here is we have this peroxyacid which has 3 oxygens involved. One of these reactive oxygens is going to basically come in and separate one of the carbons out of the way so we can connect directly to the carbonyl carbon. If we look here, we have a CH3 Methyl and here we pretend that this bond doesn't exist because one of them is going to have to move out of the way. So, if we pretend this bond is not there, then this carbon technically is only connected to 1 carbon, this carbon, so it's primary. So remember, methylcarbon moves out of the way before, a primary carbon moves out of the way before methylcarbon. So, the extra oxygen here would basically shoot in, move that carbon out of the way and implant itself right here so it can connect directly to the carbonyl carbon. But don't worry, that primary carbon over here would still be around. Here, let's see one carbon, you'd still have the same chain, 1, 2, 3. So that's what we have to say here. So Baer Villiger would be the way to change this ketone into an ester. Now remember, I told you that there was another way that we could have changed a ketone into an ester because I said there were a couple of ways. Here, it wouldn't be possible to make this particular ester in any other way. But we could have gone from this ketone to this ester, this particular ester by a different method. Here what we could have done is we could have done a reaction which we call the halliform test. Once we made the halloform test, that would change my ketone into a carboxylic acid. We would then change our carboxylic acid into an ester which we do know how to do. We'd use an alcohol over acid catalyst. And in that way, we get that ester that we need. Now, we'll come upon a question like this later on as we talk about alpha substitution reactions. But just realize these are the 2 major ways to make a ketone into an ester, either doing Baer Villager or doing this method where we use the halloform test followed by changing the carboxylic acid that we form into an ester. So, these are the 2 major ways to do these types of transformations.

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Provide the necessary reagents for the following transformation.

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