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

Question

Show how you would accomplish the following synthetic conversions efficiently and in good yield. You may use any necessary additional reagents and solvents.

(b)

Accepted Answer

Hey everyone and welcome back show how the following conversion can be achieved with a good yield use any necessary regions. The starting material is essentially ethyl benzene right? We understand that we have benzene ring with an alcohol substitution and we are forming an AL to hide out of it. Notice how nothing really changes except from the fact that this implicit hydrogen is replaced with an AL to hide. Ok. So essentially what we have to recall here is that we're performing the gap german Kash reaction. This is how we can replace one of the hydrogen atoms within the benzene ring with an AL to hide group. So we have to perform the government Kash reaction. Now let's keep that in mind. However, we want to achieve that conversion in good yield. Recall that an alcohol submission this Ortho and power directing whereas the power of product would be the major one. So we just performed the gutterman Kash reaction immediately. We will not be able to get the major product at the Ortho position. That would be the minor product because the major one is power substituted due to a minor stereo hindrance effect here. So we have to first of all keep in mind that we need some sort of a blocking group which blocks the power position and then we have our substitution at the Ortho position. So before we think about the human cost reaction, let's keep in mind that sulfur nation allows us to block a specific position and this is indeed what we are going to do here. First of all, we'll keep in mind cell phone nations. We are going to block our power position. And then when we block our power position, we are going to perform the government Kash reaction to add our Allah hide. And as our third step, we are going to essentially deep protect or basically perform diesel for nation, which will allow us to restore that hygiene and disposition. So we have three things to consider. Let's begin with sulfur nation. So now if we retried the starting material, ethylene benzene, the very first reaction that we want to perform is the cell phone ation reaction. So we're going to add our equilibrium arrows because sulfur nation is reversible and we have to keep in mind that and we're or sulfur nation to work. We have to use fuming sulfuric acid. So, are you going to his fuming sulfuric acid which is a mixture of sulfuric acid in equilibrium with S. So three sulfur trioxide. Right. So in this step because our ethel substitution here is Orson power directing and we already discussed that power substituted product will be the major one. We're essentially going to add our cell phonic acid group at the power position. So let's redraw the structure and let's add our S. 03 age group at the power position. So now essentially it blocks the power position from further substitution. So the only available positions for an additional electric melodramatic substitution. Those will be our Ortho positions essentially recall that symphonic acid group is matter directing, right, is basically deactivating and then our alcohol substitution is also part of directing. So the only position that we have for substitution is actually worth the position. It doesn't matter which one you think about because the structure symmetrical, the two positions are equivalent to each other and this is where we arrive at step number two. You want to perform the Galman cautious reaction. So first of all, let's at the regions required for this reaction. First of all, we want to make sure that we are adding carbon monoxide in the presence of hydrochloric acid and we're catalyzing the reaction using aluminum chloride And copper, one chloride. Now, first of all, we're going to draw the product and later on we will just discuss the mechanistic steps now in the Guatemalan Kash reaction, we're going to replace one of our hydrogen is and we already know which one with an alga hide group. So let's see that we get our benzene. We are going to add our cell phonic acid group and how does hydrogen is basically replaced with an alga hide. So we're going to see each group. Now let's understand how this reaction takes place before we move forward. So basically if we go down, we understand that one of the starting materials, one of the starting materials is carbon monoxide. Okay, so let's draw carbon monoxide that will be our ceo there'll be triple bond between carbon and oxygen. We have to recall that there's a lone parent, carbon, a lone pair on oxygen and carbon has a formal negative charge. While oxygen has a formal positive charge. Now we are using hydrochloric acid. So there will be proton capture by the lone pair in carbon. And we're going to indicate that. So we essentially have an attack hcl than chloride leaves. Now in this step, we can show the result on structure. So let's use equilibrium arrows because we're going to analyze an equilibrium stop for the first one. We understand that rBc each one created. So let's see that. Let's draw it. That would be carbon still triple vanity oxygen. Let's not worry about the loan paradox general, let's just keep going And now we are going to add that carbon hydrogen bond. Right, okay. Now, from here, it's really important to think about the next step. Notice how this structure is resonance stabilized. We can essentially use this pi bon and d localized the shared pair in the form of a lone pair on carbon. And we can say that from here we control our resonance form. So that would be carbon double one oxygen. Now and that carbon atom would now have a formal positive charge. Right, Because it would essentially corresponds to three bonds for minus three bonds that gives us a formal positive charge. And the chloride and I informed previously would essentially attack it to form an unstable formal chloride. So let's see how that looks like. We're going to indicate that there's equilibrium. Okay, now this structure is unstable and we are going to use aluminum chloride. Okay, to form formal cast iron. And essentially you may recall that aluminum chloride contains a vacant orbital within aluminum. So we are going to use it as our Lewis asset or basically electron, except er now the lone pair on chlorine would be used in that coordination. From here, we're going to form our complex. So let's try it. Now, chlorine would have a total of T bonds. So it has a formal positive charge. Aluminum has a formal negative charge. It has four bonds. And from here we can have loss of the leaving right. We can essentially say that we are forming our formal career Ryan. So, let's try it. Okay, so let's make sure that it's also given them blue. Okay, so you may notice that this structure corresponds to the previous one that we got during residence. The reason why we needed this additional step is because we want to make sure that we are shifting towards the formation of that Orion. And the usage of aluminum chloride essentially allows us to make sure that we get a sufficient amount of this specific formal care Ryan And now that we get our formal Karen, you may notice that it's basically a good electro file for us. So, when you think about the benzene ring or in particular whenever you're thinking about our actual structure, we can just retry it. We already said that we have our substitutions. So that's our ethyl group. That's our S. 03 age group. And then we have that attack on the electro file. So you can troll that possibly charged carbon. And this is where we have our attack reforming that carbon carbon bond. We essentially want to d protein it the result an intermediate with the chloride and iron afterwards. But you may clearly see how we are forming our AL to hide from here. So those are simple steps that explain how the reaction works. We already saw that we got our al hide using this reaction. The steps were given below. And from here the last thing that we want to do is just deep protected. We're basically from the cell phone nation. As we said for our step number three and to perform the cell phone nation, we just want to make sure that we're using heat and a strong asset. So we can say that for this step we are going to use a strong asset strongly as the conditions in the presence of heat. That's really important. And this will allow us to replace our symphonic acid group with hye jin's. We're going to restore that position are basically open it up again. So let's draw our final product. We have our six member ring that's our Benzene ring. We are replacing our symphonic asset group with hydrogen. Now we have our ethical substitution and we're just going to add our Aldo hide group. Let's not forget to add hygiene a disposition right? Basically. I missed this hygiene here. So let's keep it in mind. And then in the final product, we can also see that this hygiene is reflected because we are forming an AL to hide. This would be our final reaction scheme. And based on the outcome, we can conclude that the correct answer to the multiple choice question is C step number one addition of fuming sulphuric acid to protect the power position. When we protect it, we perform the government cost reaction to create an AL to hide at the north Pole position. And finally we open up the power position using a strong acid and heat. I hope this video helped you. And I'll see you in the next video. Thank you for watching

Show how you would accomplish the following synthetic conversions efficiently and in good yield. You may use any necessary additional reagents and solvents.
(b)

Key Concepts

Electrophilic Aromatic Substitution (EAS)

Reagents and Conditions

Regioselectivity

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