Everyone, in this example question, it says, "Draw one of the products of the following ring closure metathesis reaction." So here we have dodeca-1,11-diene used with Grubbs catalyst. Now, the way you approach this question is that we're going to draw these two double bonds near each other. So here goes, one double bond this way and another double bond that way.
What we're going to say here is the remaining chain is 1, 2, 3, 4, 5, 6, 7, and 8. So we're going to say, 1, 2, 3, 4, 5, 6, 7, and 8. Alright. So if we number this, these long chains can be difficult, but just realizing the way we're trying to create our product at the end, we're kind of aligning them in a way that looks like we're making 6-membered rings. And remember, we're going to cut through these bonds here.
As a result, these two carbons would double bond, and then these two carbons would double bond. This would give us, plus this alkene as a side product. We're really interested in the ring closure. So this would be one way. Now, here we could also in this case, we see that around this double bond, the bonds are heading in the same direction.
But we could also do it in a way where they look more trans or E actually in terms of their isomer. So, how do we do something like that? In that case, if you're trying to make a more E-type isomer, this is how you'd arrange them. You'd have one double bond this way, another double bond that way, and still count to 8. So 1, 2, 3, 4, 5, 6, 7, 8, and then we connect right here.
In this case, again, remember you're cutting through. When you do that, you're going to create another ring. In this case, now here goes our ring. And here now, the double bonds would be more like this. Taking more of an E-type of isomer, where it looks like around this double bond, one bond orient this way, one orient that way.
Plus our simple non-substituted alkene. Alright. So these are our two rings that are possible based on our starting material. Alright. So these will be our two answers for the large rings that are created.
