 Let's try this one for the first problem of the day. So remember we're on alkene, so this obviously is going to be a reaction with an alkene, and hopefully you guys can see the alkene right there. So alkenes remember a double bond, so this one happens to be a terminal alkene because this is a CH2. You want to think about it? It looks like that. Okay, so when we react, recall from last lecture, when we react hydrogen with an alkene in the presence of the palladium carbon catalyst, what'll happen is we're going to get so you can think of this as like some sort of pseudo mechanism, even though it's not really proven or anything like that. You can think of the hydrogen gas coming down, and once it gets in the presence of the palladium on carbon, it'll kind of react to form some sort of complex that looks something like that. This is an idealized form of it, of course, and then recall your alkene is going to come down. So if you want to think of this like this and react like this, giving you the syn addition, okay, and then of course the catalyst is back unchanged. Okay, so that's like a pseudo mechanism. So you would expect to form the syn product here, the syn hydrogenation product, and you do. But in this case, there are going to be two of them. Why? Because we've got this methyl group here pointing up, pointing towards us. So we can have the hydrogen add from the top side here or from the back side. So let's draw those two isomers. So if the hydrogen added from the back side of the board, we would have it like that. If you wanted to, you could think of this one as adding back, too. But of course, there's no stereochemistry associated with that. And you'd also get the other isomer, cyclopentane. So if this one added from the back, then this one, of course, it's going to give you the other diastereomer and add to the front. It gives you a molecule that looks like this. And then it asks, well, what's the major product of this reaction? So which of these two products is going to form in the greater amount or have the greater yield after the reaction is over? Well, remember steric hindrance. So two things can't occupy the same place at the same time. So since this is pointing up, this methyl group, well, let's look at it on here. Since this methyl group is pointing up, it'd be harder to react from this side. Why? Because you got something that's kind of blocking the reaction from this side. Okay. But on the other side, there's only a little hydrogen. Hydrogen is very tiny compared to the methyl group. So there's something that's very less sterically hindered that's blocking you. Okay, so in other words, it would be easier to add from the back side than from the front side, back face instead of the front face. So since that's the case, hydrogen added from the back on this product. So this one would be formed as the major product and obviously the minor product. What do you have? Questions? Any questions? Nobody wants to talk? Okay