Show how you would accomplish the following synthetic conversi...

Question

Show how you would accomplish the following synthetic conversions.

(a)

(b)

Accepted Answer

Hey, everyone and welcome back in today's video. We are going to tackle the following problem which reads show how to accomplish each of the transformations shown below. Starting with reaction number one, the starting material is an alcohol, right? We have psycho hexagonal producing an ether because we have an oc three group, right? There is this myth oxi group bonded to psycho heche cell submission, meaning we are forming an ether out of an alcohol and recall that the very common way to do that is to perform the Williams on Ether synthesis. Now, we may simply understand that the Williamson ether synthesis requires us to use an elk oxide and iron R one modernity oxygen with a negative charge. That's our elk oxide. And we want to ideally use a primary substrate. In this case, we can say our two bonnets, a good living group that will be blooming, for example, even though you can choose another halogen except from Florence, of course. So what's happening here is that we have an essence, a reaction where Alcock side attacks the electra Felix centerfold by the loss of the leaving group and we are forming our ether. So in this case, we can easily understand what our substrate should be. If we break apart the final product, we notice that we end up with a metal group and our psycho Hexcel substitution. So we are going to choose oxygen bonded to cycle Hexcel itself because that would give us a primary substrate, which is a metal group bonded to a good leaving group. In other words, we can say that if we start with our alcohol cyclo hexane, all we first of all want to produce our elk oxide. So if we draw cycle hexagonal, we want to displace that hydrogen. And for milk oxide. And the very common way to do that is to treat our alcohol with sodium because sodium will be able to displace hydrogen. And therefore, here we are forming our elk oxide and ion well done. So we have our Elcock side, all that we need. Now is our al kill bromide, our primary substrate. In other words, right. So if we want to get our primary substrate, we can essentially say okay, looking at the ether given there's a metal group, meaning we want to bond bro me into that metal group too, obtain our primary substrate. And as a result, the next reaction we want to perform is the addition of methyl bromide. So that would be a judge three C B R. That's how we can state that, right? And now because it's an essence to reaction, the negative charge would attack the electra Felix center for by the loss of the leaving group. And this is how we could get our final product. We can say that the final product would be our desired ether. We may see clearly that this oxygen is now bonded to the metal group. And we are done. We see that this is a very basic synthesis. It just follows the Williamson ether synthesis mechanism. And this would be our synthesis scheme reaction number one edition of sodium reaction. Number two, treatment of the elk oxide and iron with metal bromide. Let's see about that. That's one and two. Okay. So moving on to the second reaction, which is a bit more complicated, we want to form, actually, we're using two equivalence of benzoyl chloride. And according to the problem, We wish to form a trans al king with two final substitutions transfer each other, right. So that's what we want. Kept saying. Now, the problem might seem a bit complicated, but we may essentially think about it this way. If we start with the first equivalent of fennel, my apologies, benzoyl chloride, what we can do here, we can essentially form a carbon compound out of it. And using theater equivalent, we can form a green yard region. And if we combine them together into an alcohol, then perform dehydration, we can get our elk in. Let's see how that works. Now, if we draw both equivalents at once and analyze the reaction simultaneously for each equivalent of benzoyl chloride. For the first line, we are going to form our carbon compound. So to do that, first of all, we want to make sure that we have an alcohol because if we have an alcohol, we can oxidize it. And so an al to hide or a key tone, right? Depending on the nature of the alcohol. So the first thing we are going to do here, we're going to treat the first equivalent of benzoyl chloride with sodium hydroxide because hydroxide is a strong nuclear file, it can participate in an essence a reaction. So we will have a substitution reaction where chlorine is replaced with hydroxide. And therefore we are getting our first product here that we Benzel alcohol, right? So we got our Benzel alcohol and as we said before we went to oxidize it, so we get our carbon compound and we definitely don't want to perform an asset because our idea is to get a carbon compound that can undergo a grin you'd reaction. So we don't want to oxidize it completely. So we need to use a mild oxidizing agents such as PCC. It was essential work for us because we want to form an al hide and we want to stop just there, right? So we want to form siege to group here, right? And then my apologies that would be final ring monitor carbon atoms. So this will be our al to hide, right? If we oxidize this primary alcohol. We will essentially get our Aldo hide at this carbon. So this will be our al to hide. Now, the question is okay. So we can use PCC for sure because we know that PCC is a mild oxidizing agent. So we can definitely use it. But for the purposes of this problem, we are going to use another reagent. So that would be sodium hypo chloride and A O C L. And it's important to understand that there is one equivalent of that and also a stable free radical that catalyze is the oxidation. So it's called tempo T E M P O. And whenever you see these regions, especially if it's controlled and if it's one equivalent of sodium hypochlorite, it stops at an al A hide and no further oxidation takes place. Even though once again, I'm giving you a heads up that you can definitely use PC seen this reaction if you want to simplify it and you're not too familiar with the region. Okay. So we have formed our Carbonell compound. Now we want to form a granular region out of the remaining one. So from the green yard region, because we already have chlorine over here, we just need to use magnesium in the presence of ether. That's how we get our Green yard region. And we can say that first of all, we are getting menzel magnesium chloride. So that's our green yard region. And now that we got our green yard region. We understand that it will essentially attack the carbon eel forming Elcock side. And now if you look at these two, they will now form a single structure. So we can essentially show that we are forming an elk oxide and ions. We can simply start by drawing how many carbon atoms do we have. Now. So if we exclude final groups, that would be one carbon atom to carbon atoms, right? So we can just draw two carbon atoms. 12. Now, carbon number one has a final group. So that would be final carbon, number one, carbon, number two. And now carbon # two has another final group. And in addition to that carbon number two now contains and elk oxide and iron. Okay. Now when we have our Alcock side and I and we can essentially protein ate it. So when we protein ate it, we get our alcohol, we're using acidic work up and this gives us our secondary alcohol. And now this is where we can easily get our alkaline, right. We can perform an acid catalyzed dehydration. We call that an acid catalyzed dehydration will always eliminate the beta hygiene that that would give us the most stable product, right? And essentially, if you think about the alc instability, your first of all going to protein it at a wage group, it will be lost to form the car Bull Karen. So we can just show the intermediate and we can say that the intermediate during the protein nation stuff that would be H two s 04 as it capitalized, dehydration requires us to use sulfuric acid in the presence of heat. And the first intermediate that you're getting is your car broke Orion. So if we draw our car broke Orion, we get to final groups with a positive charge over here. Of course, there's three bond rotations. We can form cis trans isthmus depending on the orientation. But we are interested in the major product. And of course, a more stable L king would correspond to the trans. So there's one beta hygiene that we can remove. We are not going to rotate the bond because we are interested only in the major product and the removal of this hygiene during the elimination would form a double bond here, which would give us our final products. We can say that yes, what we get is our final product. That will be our Elle king. So if we draw it, I'd be that would be it, right? So we can now outline this as our complete synthesis for the second reaction. And yeah, let's just reveal the stops once again, going back to the first reaction. It was a bit simpler. We understood that we had to form an ether starting with an alcohol. And the common way stood at is to use the Williamson Ether synthesis. So we displace that hydrogen formed Elcock sighed and said we need a substrate which is primary. So that would be metal bromide because we only needed a metal group wanted to that Alcock side, right. So the reaction was pretty basic for number two, it was a bit more complicated because we were given two equivalents of benzoyl chloride. And we said one way to do that is to make sure that we first will form an alcohol out of the first equivalent and oxidize it into an al hide, then formed the granite region out of the second equivalent, react them together to get our elk oxide. Then we, when we got our elk oxide, we formed an alcohol out of it using acidic work up and then followed by asset capitalized dehydration. We have formed our elk in this is one of the products. There is also a minor product which would be six right to final groups will be pointing on the same side. But we are only interested in this product according to the problem. So we have only showed one of the possibilities. Okay, well done. So we may simply conclude that the correct answer choice to the small cultures question is B however, if you have any questions, don't hesitate to leave your comment down below in the comments section. And thank you for watching.

Show how you would accomplish the following synthetic conversions.
(a)
(b)

Key Concepts

Nucleophilic Substitution

Reactivity of Alcohols

Mechanism of Ether Formation

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