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

Question

Predict the products of the following proposed Diels–Alder reactions. Include stereochemistry where appropriate.

(d) Chemical structures of two reactants for a Diels-Alder reaction, featuring OCH3 and CHO groups.

Accepted Answer

All right. Hi everyone. So for this question we have to determine the structure of the major products in the given chemical reaction, showing stereo chemistry if applicable. So let's begin by looking at our starting materials. Right? And what I want to bring to your attention is that on the left side we have a dying right? Because we have two double bonds within the same molecule. And on the right side here we have a Diana file. Now a dyno file is an all keen or sometimes an all kind that is going to have a high affinity for dying's. So this combination of dying and dying. A file indicates that we're talking about a deal's alder reaction. Now recall that deals all the reaction is also what we call a four plus two cyclo addition. Right? Because in a four plus two cyclo edition, what you're doing is you're making a six member ring with four carbon from your dying and two from your Diana file. So four plus two. So with that being said, let's go ahead and illustrate how these products are going to form with our starting materials. That I went ahead and I redrew on the bottom here. So if I label some of these carbons so that we can talk about them during our mechanism. You'll notice that we have four in our dying and five in our Diana five. This is going back to our discussion of four plus two cyclo edition. Right? So this is a concerted mechanism. So let's get started. And the first thing that's going to happen is that our Diana file. Um the word Diana File means dying lover. Right? So it has a high affinity for the dying and it's actually gonna go ahead and attack our carbon one. So carbon six is going to attack carbon one like so and that's gonna cause kind of a cascade. Right? So the um the pi electrons in between positions one and two, that's gonna jump in between carbons two and three, Which is therefore going to push away the pi electrons between Carbons three and 4. So the pi electrons in between Carbons three and 4 are going to go ahead and jump towards carbon five which recall is electron deficient after our very first step. So with that being said, we know that this is how our six member ring is going to form and we're going to have a double bond in between um carbons two and three. But this is not the whole story. Right? Because are dying and dying. A file, their substituted and they're not symmetrical. So we have to consider the radio selectivity of the deals all the reaction. So recall that when you're talking about the deals all the reaction, um you can have either The 1 2 edition or the 1 4 position. Right? So what could happen is that you can have substitue ints on positions one and two or you can have um substitue ints on positions one and four. So in order to figure out right where um what registered activity we're talking about in this problem, we have to consider our substitutes themselves and how they affect um your polarity. Right? Your die pool moments. So let's begin by considering our fennel group on our dying. Now fennel groups which contained carbon is actually going to be electron donating towards are dying. So our fennel group is going to have a partial positive charge because it's donating electron density away from itself and towards the carbon of the dying. And therefore write the carbon of the dying that's receiving these electrons is going to have a partial negative charge. So now let's proceed and um talk about our diana file really quickly. So our diana file has an oxygen. Right? And our oxygen is going to have a partial negative charge because its electron withdrawing its greedy, right? It's gonna go ahead and take electron density away from our carbon and towards itself. So that means therefore that the carbon oxygen is attached to is gonna have a partial positive charge because now it's electron deficient. So now because we can see that our partial positive carbon and our partial negative carbon are aligned. We know that the 12 addition is going to be favored because we have this nice alignment between our partial positive and are partial negative carbons. So with that being said, um let's go ahead and redraw our six member ring. So this is going to be our six member ring. And don't forget that we have a double bond now in between Carbons two and 3. So now we've established that it's a 12 edition, right? Because we're going to have substitutes on positions one and two, they're going to be in the Ortho position relative to each other. Right? So over here they're going to be on the same side of the ring and they're actually going to have stereo chemistry associated to them, right? Because what I want to bring to your attention after I write this down is that in the beginning of the reaction, carbons one and six are each sp two hybridized. That means the tribunal planer and stereo chemistry is not initially relevant. But now in our final product, they're sp three. So, stereo chemistry is now relevant and therefore we're going to have a mixture of Ananta mirrors. So I'm going to scroll down to draw our an entire year because like I said before, stereo chemistry is now relevant given that um are carbons that are substituted, are sp three hybridized, This is our double bond and now our Nnt mirror is going to have our substitutes below the ring. This is our final group. There we go. So, now, with that being said, um these are going to be our products, right? We're going to end up with a thick mixture Or in other words, a mixture of two Ananta Mears. So um with that being said, if you stuck around till 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. Include stereochemistry where appropriate.
(d)

Key Concepts

Diels–Alder Reaction

Stereochemistry

Electron-Withdrawing and Electron-Donating Groups

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