Draw the structures of the aldehydes that might be oxidized to...

Question

Draw the structures of the aldehydes that might be oxidized to yield the following carboxylic acids:

c. CH₃CH=CHCOOH

Accepted Answer

Welcome everybody. Our next problem says, provide the aldehyde that must be oxidized to produce meth acrylic acid. And then we have a condensed structure that's written H two C double bond C and then in parentheses C three. And then coo H and we have three different condensed structures written out as A B and C and choice D is all of the above. So rather than try and read them all out, now we'll come up with our own structure and compare it to our answer choices. So the first thing to do is to expand this condensed structure a bit to just be able to visualize the structure a little bit better as we work our way back to the aldehyde. When we see the Coh group, we know that we have a carboxylic acid and we know that a primary alcohol can be oxidized to become an aldehyde and then a carboxylic acid. So we're looking for that intermediate step that aldehyde that is oxidized into our carboxylic acid product. So let's expand this commenced structure a little bit we start with and I'm going to start with the CC double bond. So the CC double bond. And then the carbon on the left has two hydrogens. We'll just write that in as H two C and then the carbon on the right, in the double bond has two R groups. It has a methyl group that's written in parentheses. So we'll put that up on top and then a coo H which is a carboxylic acid group. So it means we have a bond to a carbon which has a double bond to an oxygen and a single bond to an oh, so that's our car back silic acid. And then it's pretty simple to see when we've written it out like that. If we want to provide the aldehyde, we just know that this carbon instead of the hydroxy group will have a hydrogen. So working our way backwards, the aldehyde will be H two C double bonded to ac with that methyl branch and then it will have a bond to a carbon which has a double bond to an oxygen and then just a single hydrogen. So here is our aldehyde. It's going to sort of put a little cloud around it. That's our aldehyde. So now I need to compare it to the condensed structures offered as answer choices, remembering there's that option of all of them being correct. So let's look at choice. A, it says H two C double bond C with CH three in parentheses. And in CH two, ch O, well, the cho is correct. That's how you'd write an aldehyde and condensed structure. But note, it shows that the carbon bound to our car, our aldehyde, it's written as CH two. But if we compare that, I'll use a little red highlighting to our more expanded structure, that carbon has four bonds on it already. It has a double bond. It has a single bond to the methyl group and it has a single bond to the aldehyde group. So it cannot have any hydrogens on it. So there shouldn't be an H two there in that car. So choice A is not correct. Now, let's look at choice B, it says H two C double bond C and in C three in parentheses and then it says C H2O H Well, in this case, that structure would be the alcohol that we started with. So the aldehyde came from an alcohol. So that, that structure that we're looking at, I'll just draw it. That expanded structure would be H two C double bonded to a carbon with the methyl group. And then it would have another carbon with just an oh group instead of that Devan to ac and the carbon with the alcohol group on it, spread it out a little bit, would then have two hydrogens since it just has two bonds, one to a carbon and one to an oxygen. So Choice B isn't correct because that's the structure of the alcohol. But our question asked us to look for the structure of the aldehyde. So obviously, we know choice D all of the above is also incorrect since we have two incorrect answers already. So choice C must be our correct answer. And indeed, when we look at that structure, it says H two C double bonded to ac with in parenthesis, CH three and then cho so that is our aldehyde with the correct number of hydrogens on it. So choice C is our correct answer. See you in the next video.

Draw the structures of the aldehydes that might be oxidized to yield the following carboxylic acids:
c. CH₃CH=CHCOOH

Key Concepts

Aldehydes

Oxidation Reactions

Carboxylic Acids

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