Suggest a reagent and a reactant that could be used to form th...

Question

Suggest a reagent and a reactant that could be used to form the following molecules by conjugate addition of a cuprate. There can be multiple possibilities.

(c) Chemical structure of a molecule featuring two aromatic rings and functional groups, illustrating conjugate addition concepts.

Accepted Answer

All right. Hi, everyone. So this question is asking us to choose the reagent and a reactant pair that could be used to form the compound below. And here we have six cyclo buttal seven methyl octane 40 and pictured on the screen here are four different answer choices labeled A through D. All right. So let's go ahead and start discussing the reaction listed here in the answer choices. Now, I went ahead and I read you the starting material or excuse me, the intended product because I want to make sure that all answer choices are visible on the screen. Now, in additional, excuse me, in addition to having multiple organic molecules, right? For each pair, we also have an organo coup rate listed in every single answer choice. Recall that organoids are otherwise referred to as Gilman reagents. Now, Gilman reagents can be used to create new carbon carbon bonds. Now, specifically if you recall Gilman reagents are known for reacting specifically with alpha beta unsaturated car bal compounds. So an alpha beta unsaturated ketone is an example. Now, what does that mean when I mention alpha beta unsaturated? Let's say I have a key tone like the one shown below. I have a five carbon chain with the carbonel on position two recall that the alpha carbon is the carbon directly adjacent to the car bono itself. Whereas the beta position is next to the alpha position, but farther away from the Carbot, an alpha beta unsaturated ketone is a ketone with an additional a keen in between the alpha and beta carbons. Now, in the case of the reaction being described, the R group of the organo crate adds itself onto the beta carbon. So in this case, we're going to analyze the structure of the product and locate the beta positions that are possible right here, we have the car bono here on position four. So on either side of it, we have two alpha positions and we also have two beta positions relative to the car bono itself. Now, relative to the car bono itself, there are multiple different R groups that can be added onto the beta position. And also we can use the beta position on either side to extend the carbon chain. So all we have to do now is check the answer choices and make sure or rather check whether or not it makes sense. Now, starting off with Andrew choice A right, the akin in this case is to the left of the carbo. Now this could be correct considering the parent chain has the same number of carbons and the methyl substituent is in the same position. However, let's consider the Gilman reagent provide. In this case, we have one carbon before the Cybele group. And that is not correct because the Gilman reagent has too many carbons, considering the Cybele group is directly connecting to the parent chain. So option A is incorrect. Now, option B on the other hand proposes a similar alpha beta unsaturated ketone, but with the Cybele group already attached. Now, if we consider this perspective, in addition to the Cyclo beal group, on the beta carbon to the left, there's also an isopropyl group. And so if we look at the R group of the second Gilman reagent here, we also have one additional carbon, which means that this is not going to be an iso probable group. So because the Gilman reagent for part B is incorrect or not. Part B, option B, option B is also incorrect. Now, option C on the other hand, has a double bond in between the alpha and beta carbons that were to the right side relative to this position, an additional methyl group has to be installed. And we can actually see that in the Gilman reagent provided because the Gilman reagent for option C only has methyl groups. So option C would produce the target product. So option C is correct. But regardless I just want to very quickly discuss option D. Now option D once again has the double bond to the left. But notice how including the car bole there are five carbons before the cyclone butane ring. This is actually incorrect because if I go back to my target compound and I count the number of carbons including the car boal before the cyclone butane ring, I get six. So option D is wrong because the ketone itself is missing one carbon before the cyclone butane ring. Even though the Gilman reagent does correctly show an isopropyl group but the key to is incorrect, right. So option D is incorrect. This means that option C is going to be our answer. It is the only pair listed that would correctly produce the target compound and there you have it. So if you stuck around until the end of this video, I thank you so very much for watching and I hope you found this helpful.

Suggest a reagent and a reactant that could be used to form the following molecules by conjugate addition of a cuprate. There can be multiple possibilities.
(c)

Key Concepts

Conjugate Addition

Cuprates

Reagents and Reactants in Organic Synthesis

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