Predict the products of the following proposed Diels–Alder rea...

Question

Predict the products of the following proposed Diels–Alder reactions.

(b)

Accepted Answer

All right. Hi, everyone. So for this question, you must draw the final products of the given chemical reaction and based on the structures of the starting materials, given this is going to be an example of a deal's alder reaction, right? And the reason I know that is because our first starting material here is a dying, which is a molecule that has two all keens within it. And on the right side here is going to be a so called Diana file, right? Because our Diana file must have at least one pi bond that has a high affinity for Danes. So you're dying is going to react with your Diana file to generate a six member ring. Now, another term that we use to refer to a deals all the reaction is the four plus two Cyclo edition, right? Because like I mentioned before, we do in fact make a six member ring at the end of the reaction. And four carbons from that ring of that ring are coming from your dying and the remaining two are coming from your Diana file. So what I did on the bottom here was that I went ahead and I redrew our starting materials just so that we can see how the six member ring is going to form, right? So I'm also going to label some of these carbons because like I mentioned before, four of the carbons of our six member ring are stemming from our dying. And the remaining two stem from our Dana file, which I'm labeling five and 6. So your deals older mechanism is going to begin by first having the pi electrons in between carbons five and six attack, the dying, right? So in this case, it's going to go ahead and attack carbon one. And that first attack of the Diana file is going to cause a cascade, so to speak within the dying. So these pi electrons in between carbons one and two Are going to be pushed in between two and 3 instead. And that's going to cause the pi electrons in between carbons three and four to jump towards carbon five, which recall is now electron deficient after the first step, right? So it's this cascade of electrons That is going to generate our six member ring um at the end of this reaction. So here is our six member ring, right? And I'm going to re label it so that you guys can see that the first four stems from your dying And the remaining four remaining 2, sorry stem from your diana file. So now there's one feature that you cannot forget in a deal's older product. And it's the fact that we are going to have a double bond in between carbons two and three because um the pi electrons in between carbons one and two initially moved right, they were pushed in between carbons two and three. So that is going to reflect in our final product. Now, before we proceed with drawing out the final product, we have to remember the fact that we actually have substitue ints on both are dying and Diana file. So we must of course, draw them in our final product and we have to consider stereo chemistry always, right. So um I'm gonna go ahead and erase the labels that I drew on the right side here to open up some space for myself. And now let's talk about our substitue ints, right? Because we have to make oh groups on carbons two and three and carbons five and six are part of a ring structure, right? So what I want to bring to your attention is the fact that carbon is two and three in the beginning of the reaction R S P two hybridized, which means that their planner And when you look at the six member ring that we drew on the right side, Carbons two and 3 are still plainer, right? They are still sp two hybridized, which means that stereo chemistry is not going to be relevant for our methyl groups on carbons two and three, But the same cannot be said for the ring structure that is attached to carbons five and 6, right? Because carbons five and six are indeed sp two hybridized in the beginning of the reaction, but they are sp three hybridized by the end of the reaction, Right. So that means that carbons five and 6 are now Sp three hybridized which is going to make them stereo centers. So I'm gonna go ahead and I'm going to draw out the rest of the ring structure here. But like I mentioned before, Carbons five and 6 are going to be stereo centers. So we are going to see a mixture of an an two mirrors with this hydrogen that's going to be attached, right? So our first an anti mir is going to have those hydrogen um in front of the ring And your 2nd 1 is going to have those hydrogen behind the ring. Mhm. So I'm just gonna draw out the other an engineer on the bottom. These rings look a little weird but just bear with me. Mhm So now like I mentioned before, the method groups on carbons two and three stay the same because stereo chemistry is not relevant there, but we must of course, reflect represent I should say both and Nancy Meyers Um because carbon is five and 6 are stereo centers. So these two are going to be your final products, right? Because we do in fact have a mixture of an anti miers at the end of this process and, um, that's going to be it for this question. So if you stuck around to the end, thank you very much for watching. And I hope you found this helpful.

Predict the products of the following proposed Diels–Alder reactions.
(b)

Key Concepts

Diels–Alder Reaction

Conjugated Dienes

Dienophile

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