 Okay, so let's try this one. It says how many stereoisomers can be drawn for the following molecule? So Let's try this again. So what is the formula for this two to the end power two to the end power, right? so two to the end that will give us the number of Stereoisomers in most instances, okay, so you got to watch out some time So let's look well in here. What is that? That's the number of stereocenters, right? So let's figure out how many stereocenters we have so we've got one Two right is everybody agree with that because H methyl VR is different all different than this whole group over here, right? so within Equals two so the number of stereoisomers should be two to the two which equals what four four So we would think that we would have four things, right? So what would those be? Well, we would have the r r the s s right the r s and The s r so everybody agree those would be the four that we would have right, okay, so in this case what you'll find is since This stereocenter has the methyl hydrogen and bromine on it and this one has a methyl Hydrogen and bromine on it. Okay, there's nothing else in this molecule one of these Stereoisomers is going to be a miso compound Okay, so when you have a miso compound, right? It's its own Enantium so it's an anti-mer is the identical molecule of itself, okay? So I've gone ahead and built the four different structures Okay, so if we look here, let's figure out which ones we have So does everybody see so we've got one We'll show the an anti-mer's right. We see those two in anti-mer's one of them's are are or one of them Are are and the other ones s s, okay? Does everybody see the two in anti-mer's here you can pass them around if you want to and here right? Everybody sees probably the two in it right one of them's s r and one of them's r s But watch what happens when I flip one of them over Can I lay it exactly on top of itself, right? So they must be what? Yeah, or identical molecules, right? Yeah, and you can see and that was what I was going to say next that there's a plane of symmetry there So this molecule is miso the r s version of it, okay? So let's just go ahead and draw the three isomers up there, okay? And just prove to ourselves once again that there's only three so this one has the Hydrogens in the back so already Right, so we've got so this one should be the r s or s r with your way of drawing All right, so we've got one two three What is that? And then we've got Hydrogens are we about one two three, right? No, what is that? Yes, okay, so we see that That's the RS and remember right RS when I flip it around is the s r. Okay, so that's the same molecule. So in this case this doesn't work why because the RS equals s r Why? Because it's a miso compound. Okay, so the last thing I want to do is look at the two That are the enantiomers the r r and the s s and you should be able to tell yeah Those two are an anti-merge just by that designation, right? Watch what try what I what happens when I try to lay them on top of each other, right? Are they super imposable? Do you think no, they shouldn't be they're gonna be opposite of each other Okay, there's no way you could turn these to make them super implausible on each other. Do you want to try? Okay, any other questions on this one? Okay, so you got to watch out for those miso compounds. Okay kill it