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

Question

Show how you would accomplish the following synthetic transformations. Show all intermediates.

i. hex-1-yne → hexanal, CH₃(CH₂)₄CHO

Accepted Answer

Hey everyone and welcome back to this video. We are going to solve the following problem. Show how the following synthetic transformation can be accomplished and give the structures of all intermediates butte one iron forming beauty channel. If we draw the structures that were given meat one, iron essentially implies that we have an alkaline with four carbon atoms. The triple bond starts at position number one. So we have two carbon atoms. Already we are going to add two more. So that's 1234. Right? That's built one. I going from beat 19. We are forming beauty channel which is an al behind. So we have a carbon group hydrogen bonded directly. This is our carbon number one. We are going to have three more carbon atoms. That's a synthetic transformation that we want to perform and we have to understand that the AL kind that we have here is the terminal AL kind and we are forming an AL to hide. We call that one of the ways to formaldehyde from a terminal AL kind is to use a hydro operation oxidation reaction. This would indeed give us an intermediate which is an Enel, right, but we will see this just in a bit. Let's just understand what kind of regions we're using in this reaction. So there are two steps to perform that reaction number one is to add die Simon boring and then followed by the addition of hydrogen peroxide and basic conditions. So hygiene peroxide hydroxide. This would be our synthesis scheme. Now let's see why that works for us in the first step. Whenever we're thinking about hydration oxidation similarly to what we have using boring and tetra hydro Furin with Calkins, this terminal AL kind will form an intermediate and we can draw that intermediate by showing the first step of the reaction. If we add by siamo warren, we have to recall the ante Markovic of regional chemistry here because that's really important. Whenever hydro vibration oxidation takes place, the ante Markovic of regional chemistry is observed. Right, let's use that shorthand notation because this is what we frequently use meaning when you think about it, hydrogen must be added to the more substituted position. So we may just say that we're going to form carbon hydrogen bond over here and specifically this position will contain B saya. Now, this is because one of the hydrogen atoms is already used. Right? Remember that there's this born hydrogen bond and we are just adding this molecule across the pi bond and it's an arrangement. Right, So this is really important for us to understand now what we're going to do. We're going to draw the result on the elk team because we're using one of the pi bonds for this. In addition, there will be a double bond present now. So if we draw that al king, we may start by drawing the double bond, there would be warren bonnet over here hydrogen over here because that's in addition. And then on the other side, we would have the ethyl group as well as another hydrogen. Now this is one of our intermediates in the second step, we are essentially adding hydrogen peroxide and basic conditions. So that would be hydrogen peroxide in the presence of hydroxide. And in this step, this is where we are essentially replacing our boron with hydroxide. We're going to form double bond. Now here we are going to add our alcohol group which are places born hydrogen here remains our ethyl group and then we have another hydrogen a disposition. However, we call that this is an N. All right. It has a double bond adjacent to the alcohol group and Enel's are unstable. This is a significant intermediate because it's not really stable compared to the previous one. So, we may recall that there is always this equilibrium between the keto in all form, which always favors the formation of a ketone or an alga hide. So here in particular, we have that taught summarization basically what happens here is that we have a proton transfer and we can essentially label this proton separately. So let's expand that auction hydrogen bond. And what's happening here is that the lone parent oxygen tends to form that carbon will bond. And because we're forming that bond, the adjacent pi bond must be broken. So the pi bond is then used for the protein ation and oxygen hydrogen electrons within that bond. They're used in the formation of a new lone parent oxygen and this is how we get our Aldo hide notice if you think about this compound, we have 123 for carbon atoms. And the alcohol group starts at position number one, which now becomes a carbon carbon hell group with an adjacent hydrogen atoms. So this is indeed our alba high. That makes sense. Right? So we clearly see that to convert but one eye into beauty and I'll we can just perform a hydro operation oxidation reaction because it follows the ante Markovic of regional chemistry, we need two reactions. The first one is the addition of thy CML boring and the second reaction is the addition of hydrogen peroxide and basic conditions. The intermediates are all shown over here. Right. One of them is an unstable email which undergoes summarization to form a more stable carbonell compound. Whether it's an al to hide or a key tone, this is the general subject he always wants to keep in mind. Now the correct answer to this multiple choice question is d 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 transformations. Show all intermediates.
i. hex-1-yne → hexanal, CH₃(CH₂)₄CHO

Key Concepts

Alkyne Hydroboration-Oxidation

Markovnikov's Rule

Synthetic Pathways and Intermediates

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