 Okay, so let's try this ring forming reaction. Is this reaction on one of the quizzes or anything like that? It's just something you found in the book. Okay. Yeah, so let's try this ring forming reaction. We'll do the mechanism for it. Okay, so notice what we've got here. We've got an aldehyde. Well, it's a bifunctional thing, right? You've got an aldehyde here and you've got the alcohol here and what hopefully you see is that it's going to do this, you know, cyclic ring formation. It's going to react with itself. And it's going to make what we call an acetal here. So effectively what you're doing is masking this aldehyde as an acetal. So let's go ahead. Can I erase this one? Let's go ahead and do this. So, of course, the first thing, it's probably going to be a protonated ethanol that's going to protonate the thing because ethanol is your salt. So let's just start with the protonated ethanol. Okay. And you've got the acid-base reaction, of course. So when I do that, I've got this structure, right? So remember, we've been calling this thing like the super electrophile, right? So, and also recall that it's easier for yourself to hit you in the face than it would be for somebody else to, right? So if you take in mind both of those things, you should realize that the speed of the nucleophilic attack of this oxygen is going to be much more than that, especially because you're making a one, one, two, three, four, five, six-membered ring, which is one of the quote-unquote magic numbers in organic research from five and six. Okay, so what's gonna happen? We're just gonna take those electrons. It's gonna see that super electrophile and it's going to attack it. When we do that, we're making the six-membered ring. So if you prefer, you can label your oxygen as six, right? So oxygen, five, four, three, two, one. Okay, so on atom six, there's still a proton like that. On atom five, there's nothing, four nothing, three nothing, two nothing, one, yes, there's something, right? Well, there's the OH group, the hydroxyl group that we've made. There's the hydrogen still, okay? And of course, there's the two hydrogens on all of those, but let's just kind of focus on that. And of course, you're making a stereo center here, but we're not gonna worry about it right now. Okay, in fact, you're making both an anti-mercine. But this is an intermediate, so it's kind of cumbersome when you're trying to put all of the enantiomers of intermediates. Okay, so you've got remember, the protonated ethanol also is your catalyst for this reaction. So you're gonna, in this case, reform the catalyst again, even though you're not done with the reaction. And now we've got the protonated ethanol again, like that. And remember, if this thing gets protonated, then we just go backward. So the other one get protonated, then we can keep going forward. So the protonated, so notice, what do we have there? Very stable small molecule. So that's a good leaving group, right? But we also have alpha to that leaving group, something that will kick it out of there. Remember, if something could kick it, it'll kick it, okay? So I think this is where I mean, people like to make those things leave by themselves, you know? But if you've got a heteroatom alpha to it, it'll always kick it out. Okay. So like that, like that. And effectively, that's the reaction that drives the thing forward, because there's so little water relative to ethanol in there. So we can effectively put a forward arrow there, if you want. And if you wanted to, I know you like to sometimes, but minus H2O, okay? I'll just put it over here somewhere. So, so that's what we've made now, right? We still got that hydrogen on there. So it's kind of like a pseudo-aldehyde, right? Prodenated, kind of prodenated. We've got water in there that we just created. But like we said, right, the amount of water is effectively nothing relative to the solvent, which is in this enormous concentration, right? So it's a competition between effectively a billion to a 1, even more than a billion to 1. So the billion is going to win out. So it's going to see this super electrophile again, attack it. Like that. I'm going to make that stereocenter again. I'm just going to put a little star on that stereocenter that we made. Let's just star this. There. And in fact, let's go over here and star that. Because those are stereocenters too, right? It's just adorable. Okay, this is not the product, right? Why? Because it's got that proton stuff on it. So you can imagine maybe the water molecule, but probably not another ethanol molecule. It's going to regenerate that catalyst, either way, transfer the proton to something that can transfer the proton again, like that. And again, that's a back and forth reaction. But of course, you're going to isolate the product, the organic product. Why? Because you're going to do this in a separatory funnel, and it's going to be more soluble, okay? So hopefully you can see we've got one carbon, so that's still a series in it. I mean, let's just say show that we've got the same thing that we started off with, right? Part of that we wanted to get, like that. And then it's a plus and a two, right? Okay, so like that. So hopefully you can see we've got that stereocenter there, of course, and that that is the acetal that you're looking for, right? So two oxygens with R groups attached to the same carbon is called an acetal. So this is essentially an acetal formation. And so R groups, do they have to be carbon? Well, I mean, yeah, let's, for you guys, yes, let's just say they have to have some sort of carbon associated with them, okay? And so in this case, you went from this bifunctional thing that was aldehyde alcohol that reacted with itself to make the acetal. And in fact, you know, that's acetal formation. Anyways, you got an aldehyde or a ketone, right? And you react it with excess alcohol or whatever. Okay, so we're cool, right?