Show how you would synthesize the following compounds, startin...

Question

Show how you would synthesize the following compounds, starting with acetylene and any compounds containing no more than four carbon atoms.

a. hex-1-yne

b. hex-2-yne

c. cis-hex-2-ene

Accepted Answer

Hey everyone. And welcome back in this video, we are going to solve the following problem using a settling as the starting materials show how each of the following compounds can be synthesized on your synthesis. You can use any compounds with four or less carbon atoms. Number one beat one ein number two B two ein number three says B two. In if we think about reaction, number one, we can simply perform our general stuffs and drew our starting material which is the settling the simplest al Qaeda with two carbon atoms and we are forming beat one line essentially, that means we have an alkaline. The triple bond starts at position. Number one, there are a total off where carbon atoms because the parent implies beat 12, we need to add two more. So one That's built one eye. If we compare the two, we understand that we are forming one al kind out of the other, we're just making the chain longer. And if you notice this is still a terminal alkaline because it still has one acidic hydrogen at the left side of the triple bond, we call that there is a word basic reaction that we can perform to make a longer chain alkaline, which is a terminal alkaline by simply deep Roatan ating that is thick hydrogen and performing an essence a reaction. So let's see how that works. If we notice there is this acidic hydrogen at this position or the other position in this matter, which one you take into account. But the City Line has this acidic hydrogen and we can remove that acidic hydrogen. If we treat it with a strong base such as sodium Amytal in the meat and iron would essentially attack this hydrant forming a satellite and a satellite. It's a strong nuclear file because the strong nuclear nuclear file G is charged, it can participate in an essence a reaction and this is where you have to make sure that you're creative enough and you understand the context, right? You want to look at the product, you see that you have two more carbon atoms to be added. So you want to perform an SN two reaction where you are adding two more carbon atoms to the chain, meaning you need an ethyl substitute print bonded to a good leaving group. Now, what kind of leaving group can we choose? We can use a standard good leaving group which is booming. It's good for us, right? You can choose chlorine, it's fine as well. So the negative charge would attack that Electra Philip position for by the loss of the leaving group. And that's how you're going to add two more carbon atoms to your chain and you're going to obtain Butte 19 and you are done. So we can say that for reaction number one, it's just sufficient used to Steps. Number one is addition of sodium A might to produce a satellite. And number two is the treatment of satellite with ethyl bromide To give us beat 19. These would be the reaction conditions for number one and we are ready to proceed for number two, the main difference is that he wants to form be it tea iron out of a settling and to do that, we are going to look at a set of reactions. But first of all, let's draw the product that'd be triple bond starting at position number two. And then that means there must be two more carbon atoms on the left and on the right. Let's throw it a bit more clearly, right? So B two and 1234 carbon atoms, the triple bond starts at position number two, right. So the main difference is that this is not a terminal al Qaeda, this is an internal one, meaning we can add two metal groups replacing these two city hydrants using the previous logic. Why don't we just apply that logic and think about it this way. What if we start with a settling D protein eight at once, produce a satellite? And then if we look at the triple bond. We understand that one metal group has been added. Meaning the substrate we are using here must involve the presence of a metal group. We see bonded to a good leaving group such as bro mean we have that nuclear attack. This is once again, an sn two reaction followed by the loss of the leaving we're adding our metal group, but we need one more metal group and we still have one city hygiene. And that's great for us because if we think about it, we can once again use that strong base sodium amid, would the protein ate the remaining acidic Hytrin to form another a satellite which is once again a strong new profile. And we can repeat the process. We can say that there will be another essence, a reaction where we can use metal bromide because we need another metal group. So that would be a church. Three C B are right in the negative charge with essentially attack that Electra Philip position followed by the loss of the leaving group. And that would give us our internal al kind. That's how we get our final product. Now, we see clearly what the steps are and we can just label them appropriately. Step number one, treatment of settling with sodium a mine. Number two, when the satellite is formed, we are going to add that metal group via an sn two reaction. So we're using metal bromide, we are repeating those stops. That's it. If we once again at sodium A might to remove the remaining to the hygiene, we are just going to add another equivalent of metal bromine to ensure the addition of that group. And these are our four conditions for the required transformation. Let's label this is our final answers for reaction number two. And we are simpler, ready to look at reaction number three where we went to form six B two in. So now number three, A settle in is converted into six bit too in and says implies that this Elkin must have a double bond where the two L kill substitute prints are on the same side of the double bond. So as the name implies, beat team means that the double bond starts at carbon number two, that's good for us. And it's just because the two metal groups are on the same side of the double bond one way to form Sis Elkins. And actually, that's one of the primary ways whenever we are considering al kinds is to use landlords catalyst. So if we have four carbon atoms, suppose that you're starting with a corresponding alkaline, meaning you want to have a triple bond between carbon number two and carbon number three, because you have a total of four carbon atoms, the double bond starts at carbon number two. So you want to get a corresponding alkaline. And if we use Lenders catalyst, we are using hydrogenation in the President's office, Landlords catalyst this reaction is stereo specific, meaning it produces Sis Elkins exclusively. That's why it's so important to keep in mind that this region is powerful whenever you're dealing with Cece Elkins, this is a very common reaction to use, right? And this is how we can get our final product. This allowed us to narrow down our possibilities because now we clearly see how to get a final product and the final step. But now how do we get butte to iron right from settling. And actually, we already have the answer. I feel like at problem number two, we have the synthesis scheme for B two Ein, we need these four reactions. And once again, I'll give you the reminder that we had to D protein 81 acidic hydrogen to form a satellite perform an essence, a reaction with methyl bromide repeat the steps to add those two metal groups. So we are done, we can just use reaction number two as a huge help for us. So we can start labeling our steps because we already understand what the final step will be. Reaction. Number one, treatment of settling with sodium a mine. Number two, a satellite reacts with metal bromine reaction. Number three, once again, D protein ating the remaining acidic hygiene reaction. Number four, adding one more metal group. So this is where we get our beat to iron and are beat to iron must be reduced in the presence of hydrogen and landlords catalyst. To give us our says, Al King. That's it. Well done. Let's leave. Oh, These five steps is our final answer. Now, once again, I'm giving you an idea that we did number three so quickly because we already knew how to form beauty to iron very quickly. Number two has all of the, all of that synthesis outline. We just wanted to think how to get sis Al Keen and having in mind that landlords catalyst is required. That's it. If the corresponding Al Qaeda's B two iron and we know how to get B team from the previous step, we are done. Now, the correct answer choice to this question is D however, if you have any questions, don't hesitate, leave your comment down below in the comments section and thank you for watching.

Show how you would synthesize the following compounds, starting with acetylene and any compounds containing no more than four carbon atoms.
a. hex-1-yne
b. hex-2-yne
c. cis-hex-2-ene

Key Concepts

Alkyne Synthesis

Markovnikov's Rule

Geometric Isomerism

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