Show how each of the following compounds can be synthesized fr...

Question

Show how each of the following compounds can be synthesized from benzene:

i. 1-phenyl-2-propanol

Accepted Answer

All right. Hi, everyone. So, first question, let's show how the following compound can be prepared using the given starting material and any necessary reagents. And so our starting material here is isopropyl benzene. And in our final product, our isopropyl benzene has been substituted by a three carbon chain that has an 08 group on position two. Right. Now. What's interesting here is that our new substituent is in the position relative to our initial isopro group, right? And because we're adding something like an group directly onto an aromatic ring, we're going to have to rely on electrolytic aromatic substitution, right? So, recall that when we're talking about an E A S reaction, existing substituent greatly affect the positioning of new ones on the rate, right? So because we're starting off with our is group here, an isopropyl group is an Alkie group, right? And al groups are orthopro directors. So it makes sense that our new substituent here is being added on to the pair position relative to our Isopro group. But in addition to this three carbon chain here, we also have an alcohol, right? We have an O age group and recall that one way in which you can come up with. And alcohol is by creating an epoxy, right? And that oxide stems from a double bond that you go ahead and oxidize, right. So that oxide can be opened and you can generate an alcohol after acidic workout. So what that means for our reaction is that we have to add a three carbon chain, right? And that three carbon chain has to include a double bond so that we can create our oxide, right. So for our first step, I'm going to go ahead and redraw our starting material here are isopropyl benzene so that we can go ahead and proceed with our freedom crafts ation, right? So our first step, like I mentioned before is going to be the addition of a three carbon chain that contains a double bond. So our reagent here is going to be something like a little chloride, right? Because notice how we have three carbons and our double bond is in between carbons two and three, right. So here for Prado craft calculation recall that we still need a catalyst, right? In this case, it's going to be A L C L three. So after that process, right, what we've done is we've gone ahead and added an additional R group to our isopropyl benzene, right? And it added on to the preposition, right? Because the existing isopropyl group is an orthopro director. Now, the pairs position is favored because there's less STAIC hindrance right, it's more comfortable, so to speak, for these art groups to be on opposite sides as opposed to right next to each other. So that's why the paras position is favored. And now we can go ahead and proceed with the oxidation of our double bond, right? And recall that that occurs with MC P VA. So after treatment with MC P VA are A is going to be replaced by an oxide. So here are three carbons and because our double bond was in between carbons two and three carbons, two and three are going to be involved in our oxide. Now, here we have one last step, right, which recall is the opening of our oxide to generate an alcohol. But that last step is twofold, right? Because number one, we have to go ahead and open our oxide, but we also have to subsequently proton it, right. So there's actually two separate steps. Number one is reacting our oxide with a nuclei like hydride and sodium hydride because our hydride here has a negative charge and sodium is there is a counter ion. Of course. Now here hydride is going to go ahead and attack one of the two carbons in our oxide. And in this case, it's going to be carbon three, which is the less substituted, right. And the reason for that is because it is more accessible that way or because carbon three is the less substituted, it is more accessible for attack right. So our hydride attacking carbon three forces a pair of electrons to go towards oxygen. And so that creates and negatively charts oxygen, right? And that negatively charged oxygen is now bound to the more substituted carbon in our oxide, which in this case was carbon two, right? So now carbon two has an O minus and carbon three has our hydrogen from our hydride. So now our final step, our final step here is going to be that protonation step because we need an alcohol at the end of this process. So from here, we're introducing H C L and so now our O minus is going to go ahead and de potentate H C L. And from all this right, we end up with our final product. So all of this is going to be your final answer. All of this is going to be your final answer. So your first step was craft's cul of your isopropyl benzene to yield this all key. And this all came here was oxidized using MC PB A. OK. Now, the resulting oxide was opened after attack by sodium hydrate and that created an O minus, right? That created an oxide anion which was then subsequently proin using H C L. So this is going to be your final answer, right? And I know it was a lot, but everything that happened here happened for a reason. So if you stuck around to the end, thank you very much for watching and I hope you found this helpful.

Show how each of the following compounds can be synthesized from benzene:
i. 1-phenyl-2-propanol

Key Concepts

Electrophilic Aromatic Substitution (EAS)

Grignard Reagents

Reduction Reactions

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