One going away from our diene, that's the one on the right. This R group is coming out at us in space. So that should be a dash, for our product. And if we're staring downĪt our cyclohexene ring, I'm going to draw that in, this R group is goingĪway from us in space. These two carbons, so we get the product on the right. We know that a bond formsīetween these two carbons, and a bond forms between The one to the right of the line, this R group is going away from the diene, so that's this one on the model. So on the model, that's this R group, the one that's pointing towards the diene. Look at the R group on the left, that's the one going towards the diene. Groups trans to each other? So let me go ahead and draw a line in. And we draw the same ester in down there. So I'm just going to use two wedges, so let me put those wedges in. We could use either wedges or dashes here. So we need to have those two groups on the same side of the ring. So we get a cyclohexene ring, so let me sketch that in first, and then we think about These electrons move into here, and these electrons move down. We know these electrons move into here, so we form a bond between So let's look at anĮxample of what I mean. Now if these R groups are the same, it doesn't matter how you Up relative to our plane, if we're staring down this direction, so we put those hydrogens as wedges, if we put them in for the products. Side, these hydrogens, these end up, so they're And I think a systematic way helps you, when you're doing Diels-Alder Reaction. In how I draw my dienophile, in thinking about my product. These two R groups, would end up going down. Side of our double bond, let me go ahead and put So I'm going to go aheadĪnd put these dashes in. So those two R groups should go on dashes. Our cyclohexene ring like that, these two R groups are And if we're staringĭown in this direction at our cyclohexene ring, let me go ahead and draw in This carbon and this one, so when we look at the product, here are the two bonds I just pointed out, and we can see that our two R You know that a bond formsīetween this carbon and this one, and a bond forms between It, we have two hydrogens, and here are the hydrogens on the model. And on the right side of our double bond, in terms of how I've drawn Side of the double bonds, let me go ahead and make those red, so these two R groups, on the model, you can see What happens if we show ourĭienophile approaching our diene in a different way? In this case, if you thinkĪbout our double bonds, the two R groups on the left Of the line that I drew, in this case, two hydrogens, that ends up going down in our product.
Right side of the line, ends up as a wedge, and for the cis, all right we have aĬis alkene on the left, and those two R groups end Groups are on the right side, and those end up as both wedgesĬoming out at us in space. So if I'm drawing theĭienophile approaching the diene in this fashion, the two R Hydrogens over here sometimes, and think about the groups
So let's go back to theĭrawing over here on the left, and let's think about stereochemistry. So we're drawing in our stereochemistry, we draw in our cyclohexene ring, and we put in our R groupsĬoming out at us in space. So these R groups are actuallyĬoming out at you in space. And if you're staring this way, down at your cyclohexene ring, these hydrogens will be Movement of electrons, these two R groups end So we need to think about those R groups. This carbon goes fromīeing sp2 hybridized, to being sp3 hybridized. When we go to our product, over here on the right. So the diene and theĭienophile approach each other, and we know a bond forms between this carbon and this carbon, so think about a bond forming here. So the two R groups I made red right here. So up top here is the diene, which you could thinkĪbout as being one plane, and down here is the dienophile, which would be another plane. So what does that do for the product, in terms of the stereochemistry? How do those two R groups end up? Well down here, let's look at the picture of the diene and dienophile. Groups cis to each other, so they're on the same side. So here is our dienophile, and we have our two R So let's think about the stereochemistry of these dienophiles. The pi electrons in blue form this bond, and finally, the pi electrons in magenta are these electrons in our product. Into here to form a bond, and these pi electrons move down. Into here to form a bond, these pi electrons move We know that our Diels-Alder Reaction involves a concerted
On the left we have our diene on the right is our dienophile. In this video, we're going to look at the stereochemistry of the dienophile.
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