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Hello everyone.
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Today we're doing chapter 23 problem 52 and this problem asks to draw the product in each of these reactions.
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So let's look at a first.
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So in a we have some sort of carbonyl group with an alpha halide and then we're adding some sort of reagents that will promote elimination.
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So we know lithium bromide will dissociate in solution to lithium plus and br minus and br minus can act as a nucleophile to cause an elimination reaction to occur in which you'll pick up one of these protons making a bond and then the sigma bond will break to form a new pi bond.
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So for a, we could say that we're going to get an elimination product and when you make a bond, you break a bone, that bromin will fall off and we will form a new elimination product in which you will form both the e and the z isomer.
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So here we have we drew the e isomer, so we would also have the z with these two groups on the same side.
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So for b, we're adding heat.
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So what we know about heat is that it promotes spontaneous decarboxylations of alpha carboxylic acid group.
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So if we see here, like this is a carbonylic acid.
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So let me actually just blow this up a little bit.
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Let's give it over this.
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And then just blow this one up.
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Yeah, that's better.
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So now we see that this carboxylic acid is actually alpha to a carbonyl group.
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So when you add heat, the lone parallels in this oxygen will go to form co2, making a bond.
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You make a bond, you break a bond.
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So this bond is going to break, go to this carbon nucleus and pick up this proton to neutralize it.
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So for b, you can say that you're going to form a spontaneous decarboxylation product using heat.
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And only for carbonyl, because we have another carbacilic acid here, but there's nothing alpha to it to promote the spontaneous decarboxylation.
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Nothing is driving this reaction on this carbonic acid.
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It's just happy to stay as is, but here because it's alpha to a carbonyl group it causes it promotes it to go through that spontaneous decarboxylation to form two products and increase the entropy of the system so now you have products for b now and see what we have well let's draw c out so you can actually visualize it so for c we're starting with one two three so one two three we're starting with this group and we're using lda, which is a strong base, to deprotonate this alpha proton, and then we're adding in alkali group.
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So we're going to add those two carbons off this alpha position because we're forming a nucleophile, and these are an electrophil.
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So we'll have an s &2 nucleophilic attack to add those two carbons here to form product c.
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Now for d, what we have is an alpha halide, and we're reacting with a strong nucleophile, being this aiming group.
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So what we can actually have is just a simple s &2 backside attack with inversion of stereochemistry here.
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So for d, you just have a simple nucleophilic attack, s and 2 nucleophilic attack with inversion of stereochemistry...