Suggest the most appropriate method for each of the following ...

Question

Suggest the most appropriate method for each of the following laboratory syntheses. In each case, suggest both a chromium reagent and a chromium-free reagent.

(a) butan-1-ol → butanal, CH₃CH₂CH₂CHO

(b) but-2-en-1-ol → but-2-enoic acid, CH₃CH=CH–COOH

(c) butan-2-ol → butan-2-one, CH₃COCH₂CH₃

Accepted Answer

Hey everyone and welcome back into this video. We are going to solve the following problem, suggest the most suitable regions for the following oxidation reactions. A propane 102 propane. I'll be pro band two oh 22 propane on and see probe two in 102. Probe to email for each reaction suggest to regions a chromium based Regent and a non chromium based region. So let's start solving this problem by listing all of these three reactions Pro pan 10. It essentially implies that we have a three carbon chain and an alcohol group at position number one. According to the problem, it's being oxidized into pro panel. So we are going to draw our al to hide group right? That we see cho and then we have a total of three carbon atoms. So that's 123. Right? We have our propane al for B. We are starting with pro pan to oh so again that's our three member chain. And the alcohol group is now at carbon number two. As the problem suggests we are oxidizing it into two propane on. So we are going to draw a propane on and add the carbondale group at position number two. Right, this is our key tone. Finally see probe two in one oh. So first of all we are going to draw a pro panel once again. So that would be three carbon atoms and at position number one of the chain, we have an alcohol group at position number two. So that would be this carbon atom. We have a double bond. So starting with carbon number two, we're going towards carbon number three and adding that double bond and we are oxidizing it into probe to email Meaning nothing really changes. We still have that double bond at position number two. But now position number one as an AL the hide. Right? We have a suffix of A L. L. So that would be our AL to hide. We're going to add that all the high group over here and then we want to suggest chromium and non chromium based oxidizing agents. So starting with the first one, let's analyze the reaction. The alcohol here is a primary alcohol and we are producing an album hide. We call that if we want to oxidize a primary alcohol, internal hide and not oxidize it further into an asset. We can use PCC. Right? Pcc is a chromium based region. So let's say that this is chromium based CB. Okay, for simplicity we will use CB. For chromium based region. Now PCC is a mild oxidizing agent. So we can say PCC is a mild oxidizing agent. That's why we stopped at an AL to hide and we don't oxidize it further. In addition, secondary alcohols could be oxides to ketones with Pcc. So that's our possible regent for this transformation. That is chromium based. Okay, so we have PCC. What about non chromium based regions. We call that there are several regions which can achieve the same transformation. These are D. M. P. Or sworn oxidation. Now these two would be helpful for us. Now, what is swearing oxidation? That essentially implies the presence of two regions. One of them is the muscle sulfur oxide, the mso and the other one is ox a little chloride, which essentially looks like C O C L two times. Right? So D. M. P. And swearing oxidation allows us to achieve the same transformation. We can oxidize primary alcohols into al heights and secondary alcohols to ketones. So number one, our choice can be a PCC for the chromium based region. And for B we can use either D. M. P. Or swear an oxidation. That means we can use D M. S. O and ox allele chloride so that B C E O C L two times. So these are our possibilities, right? We can use any of these regions and we can say that for B, we can just add the fact that this is non chromium based Regent and CB non chromium based Regent. So once again PCC is chromium based. Right? It has chromium in it, D M. P. And seven oxidation. They don't have chromium in them. Well done. So let's move on to be for B. We understand that the oxidation here is the oxidation of a secondary alcohol producing a ketone and as we discussed before, P C C can be used for that purpose as well. Now. For that means for a our first choice could be PCC once again because PCC is a mild oxidizing agent that oxidizes primary alcohol sal hides and secondary alcohols to ketones. Meaning we are going to add PCC as our chromium based region. Or we can use a strong oxidizing agent. In addition to our list, we can add jones Regent, which is strong and it consists of chromium sex oxide in the presence of sulfuric acid. Now, the reason why we can also use a strong asset. My approach is a strong oxidizing agents such as jones reagent is because formaldehyde. We can oxidize them further and to assets. Right? And we don't want that. So we definitely want to use a mild oxidizing agent and party. We cannot use jones Regent. We don't want to ruin our product and oxidize it into an asset. However, for B we will stop at a key tone because we cannot oxidize that keystone further, meaning PCC is not the only choice. We can also use the jones region. So we can say our second possibility for our chromium based region is the jones region itself, chromium sex oxide In the presence of sulfuric acid. Those would be our choices for chromium based regions. And at four b. As we previously said D. M. P. And swear an oxidation. They achieve oxidation of primary alcohols to al the heights and secondary alcohols to ketones. So that works for us right? Meaning we can use the same set as before. We can say that non chromium regions would involve D. M. P. Or swearing oxidation? So that would be the metal self oxide in the presence of ox alot chloride. Those are non chromium based regions. Okay, so we got our regions for B. Let's think about C for C. We are seeing a similar scenario to a right? Because we are oxidizing a primary alcohol. This is a primary alcohol because the alcohol group is bonded to a carbon atom that only has one neighbor and we are producing an album. Hide nothing Changes with respect to that double bond. Right? That stays. We only noticed that the alcohol group itself is oxidized into an alga hide. Simply speaking, we cannot use jones regent anymore because we don't want to oxidize al to hide further. So we can only use PCC for our chromium based region. So we can say PCC is the only choice. We want to use a mild oxidizing agent. We're gonna use a strong one. And now for B once again, same thing. Right? Primary alcohol produces. And Aldo hide again, say that this is an AL to hide. And if we look at this reaction, it looks very similar today. So we can use D. M. P. Or swearing oxidation. That will be our visibility for non chromium based region. So D. M. P. Or the metal self oxide in the presence of oxy chloride. These are our non chromium based regions. So let's conclude our findings. This will be our final answers for each reaction. Right. And we are going to say that or a. Because we are starting with a primary alcohol and getting an AL. To hide similarly to see where we have a primary alcohol and producing an AL. To hide A and C. Are very similar. And that's why we can only use PCC for chromium based region because we want to stop at an AL. To hide and we don't want to oxidize it into an asset. And for non chromium based regions we can use D. M. P. Or swearing oxidation. However, for B. Because we're starting with a secondary alcohol and producing a key zone instead. The only difference is that besides using PCC, which is a mild oxidizing agent, we can also use a strong oxidizing agent which is the jones reagent. Since it doesn't really matter, we cannot oxidize a key zone further so either you use a mild one or a strong one. Doesn't really matter now. We can conclude that the correct answer choice to this multiple choice question is C. However, if you have any questions, don't have states, leave your comment down below in the comment section and thank you for watching

Key Concepts

Oxidation Reactions

Chromium Reagents

Chromium-Free Reagents

Watch next

Suggest the most appropriate method for each of the following laboratory syntheses. In each case, suggest both a chromium reagent and a chromium-free reagent. (a) butan-1-ol → butanal, CH3CH2CH2CHO (b) but-2-en-1-ol → but-2-enoic acid, CH3CH=CH–COOH (c) butan-2-ol → butan-2-one, CH3COCH2CH3

Key Concepts

Oxidation Reactions

Chromium Reagents

Chromium-Free Reagents

Watch next