Circle the aldohexoses that would produce the same wall degradation product. If none of them would share a degradation product, then just write NA. Cool. So, guys, remember that what we're basically discussing here is that wall degradation is going to get rid of your C2 stereochemistry. So whatever that C2 is going to be gone and all you have to look at is what's below C2, that's what's going to be retained. So since these are all aldohexoses, I would expect that after wall degradation, all these carbonyls disappear, right? So, those carbonyls are gone. They turn into CN groups or HCN. And then, all of these oxygens become carbonyls. Let's turn them into double bonds right now. This is going to be a little bit like makeshift but it's going to work. Just put double bonds. Double bond, double bond, double bond, double bond. Okay?
Now keep in mind, guys, what is the stereochemistry of this carbon now once it has a double bond? Trigonal planar. So, it doesn't matter what side the O double bond O is facing. It doesn't matter because it's trigonal planar anyway. So those are the same thing. There's free rotation around that single bond. Does that make sense? So, it doesn't matter. It could be the same if it's towards the right or towards the left. Another thing to keep in mind, I'm ignoring the H because it's going to eventually leave. So, like this H would eventually go away. So I'm literally just saying without a mechanism let's draw carbonyls. Cool.
So, if all these are the same, all those aldehydes left, and if all those carbonyls are the same at the top, which of these 2 are identical? Do you see any 2 of these that are identical sugars? And yeah, I do. I see glucose and mannose. Okay? Glucose and mannose will become the same exact monosaccharide because the top carbonyl is going to leave, and then they're just both going to turn into a carbonyl at that position, the blue position, and then all these other groups are going in the same exact directions. Okay? So, that's actually the answer that mannose and glucose produce the same exact wall degradation product because of the fact that they're C2 epimers of each other. And C2 epimers are lost, the stereochemistry is lost every time you do a wall degradation. Cool? Cool. So that's the end of the question. Let's move on to the next video.