Compounds containing deuterium (D = 2 H) are useful for kinetic s...

Question

Compounds containing deuterium (D = 2 H) are useful for kinetic studies and metabolic studies with new pharmaceuticals. One way to introduce deuterium is by using the reagent LiAlD4, equivalent in reactivity to LiAlH4. Show how to make these deuterium-labeled compounds, using LiAlD4 and D2O as your sources of deuterium, and any non-deuterated starting materials you wish.

(a) CH3CHDOH

Accepted Answer

Hey everyone and welcome back in today's video. We are going to solve the following problem. Do traitors. Organic compounds are useful in kinetic studies of chemical reactions and in metabolic studies of pharmaceutical drugs reducing a carbonell compound using a duty rated reducing agents such as sodium World. Due to ride is one of the many ways of producing duty rated organic compounds using sodium world. Due to ride and heavy water as sources of deuterium. Devised a plan for the synthesis of the following compound C. Six H. Five C. H. D. O. D. So let's throw that compound See sex age five essentially implies that we have a benzene ring in our structure. That's our fennel substitue into right? It's bonded to carbon atom that has one hydrogen. That's what it says age. Another atom of deuterium. So that B. D. And then we also have O. D. Group which is very similar to the alcohol group. If we think about the deuterium as hydrogen right as the first size of of hydrogen H. One. So now what we're going to do here, we're going to slightly modify the looks of the structures. We can analyze it in terms of something we are generally familiar with. What if we simply replace every atom of deuterium with hydrogen and what what if we analyze that compound? In that case we would have to hide jin's here. So that would be two implicit hydrogen. And then here we would have our oh age group. Right. And you may notice that this is a primary alcohol. No because this is a primary alcohol. We may recall that if we reduce all the hives, right? If we take any al to hide, let's suppose our one age. And if we use a reducing agent such as suppose sodium borough high tried. Right. And then our step number two would be addition of water. We produce our primary alcohol. So that's the whole idea. We have noticed that there's an alcohol over here. So we are going to form our primary alcohol that we are 10. H. Okay, so now what we're going to do here, we're going to think about this scheme. First of all, let's just keep in mind that the way this reaction works when we think about world high tried itself, We can troll BH four ride that we More of a high trite and iron with four hydrogen atoms negative charge on warren. We have that attack at the electra Philip position. And then of course we're not that worried about the mechanism. But when the pipe bond is broken essentially, the Elcock said, and I will get Putin aided by water. So we can simplify our scheme and we can say that there will be proton capture from water itself, right. H. O H. So this proton is the one that is going to be captured. So this protein and red right will be added to oxygen and this proton in green will be added to carbon. This is very important to understand. Okay, so now we understand the scheme, we understand that this is a so called primary alcohol if you wish. Right? Because whenever we replace the material with hydrogen, we get our primary alcohol. And that essentially means we can start with an al the height to synthesize it. So let's draw an arrow and let's think about our starting material. If we think about our starting material we can propose an AL to hide. So we can throw our benzene ring than our carbon atom over here. And we noticed that this carbon atom has hydrogen. Right? So we are going to add hydrogen and then our car menial group, Let's see if that works for us. Maybe this outside would be fine because as we said previously we're going to produce a primary alcohol. So this is the AL to hide. We want to use to produce this alcohol right? If we start with this alga hide, which is Ben sal to hide and if we use a strong reducing agent or a mild reducing agent we can produce our primary alcohol. But now the main difference is that we're adding a different set of atoms and these atoms are deuterium atoms. So first of all we are going to use borrow, Do you to write? So that would be BD four D D D N D. Over here. So according to our scheme, if you think about it, the first atom is added to our carbonell group and then there will be and Alcock said and I informed but of course we're not that worried about the mechanism. And we previously said that another at atom would be added from detail from heavy water. So we have D. O. D. And that deuterium would be captured by this by the lone pair of that oxygen. So we would form O. D. Here as well. So we indeed see that. We see our O. D. Group and we see that there will be this green deuterium atom now bonded to this carbon which we also see. And this is our original hydrogen atom which makes sense. Right So we understand that this at the height is indeed our starting material. And we need to step just as indicated in our scheme. Step number one we set instead of world hydrates were using borrowed DEETs. Right and step number two. Instead of using water. We're using heavy water D. O. D. Or detail right. Just as suggested by the problem to get our final product. So these are our regions. Let's just neatly rewrite our complete reaction. We have to start with Ben sal to hide. So this is our starting material and then treated with number one sodium borough. Do you two. Right and number two. Heavy water need to oh and once again if you think about it. Just one more time this deuterium will be added at this position. Right. And then when we break the pi bond form our L. Cox it and I on it will get protein aided by heavy water to produce our O. D. Group. So there will be the deuterium added at this position and the deuterium added to the oxygen by breaking the pi bon meaning we are ready to draw a final product and notice that this is indeed a product that we wanted to form. So there would be hydrogen. Right this one, the deuterium coming from borrow D. To ride. So that would be the deuterium over here And then oh D. Group formed G. To the presence of water our Elcock said and and gets protein ated. That's our OD. So that works for us. This is our general reaction scheme. We have proposed our Ben's al to hide as a starting material to reaction conditions to get our found product. Now if you notice this reaction corresponds to choice A in the multiple choice question so that's the correct answer. And if you have any questions, don't have states. Leave your comment down below in the comment section and thank you for watching

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