Suggest the reagents used to effect the transformations shown....

Question

Suggest the reagents used to effect the transformations shown.

(c) Chemical reaction showing ether cleavage, producing a phenol and a cyclic ether. Reagents for transformation suggested.

Accepted Answer

Welcome everyone. Here's our next problem. It says provide the reagents to complete the reaction below. And the reaction we have is we have here a fenny ether. So we've got the central oxygen and on one side, we have a carbon bonded to a benzene group. So that would have been a phenol before it was made into an ether. And on the other side, we have a carbon bonded to a cyclo butane group that has a methyl group attached to it on the opposite side. And we see the reaction that takes place is that we have an ether cleavage. So we end up with two molecules, the molecule with a cyclone butane ring and the methyl group now has a methanol group attached to it. And then our other product is toluene. So a benzene ring with a methyl group and we actually are provided with multiple choice options for our reagents. So we don't have to think of them out of the blue. We can choose among these options. Choice A is HBR or hydroponic acid. Choice B. We have two steps. Number one, sodium hydroxide, carbon dioxide, high temperature and high pressure and number two and H 30 plus or acid quench. Then choice C is H two slash P DC. So hydrogen gas and a palladium catalyst and choice D has three steps. Number one, magnesium, zero, number two, carbon dioxide and number three H 30 plus or acid quench. So which would be the correct reagents? Well, we know that ethers are just not very reactive. There's not gonna be too many reactions they take place in. As we said, we have ether cleavage, we've broken one of the co bonds. In this case, the bond between our uh toluene and the oxygen. And when we think of ether cleavage, kind of the most common one is reacting with HX. This generally produces two alal hides. So the ether is leaved and you end up with the halogen attached to either side and you've eliminated water. So two alkyl halides plus water is the expected product of an HX cleavage. Now, in the case of, if phenol is, if you have a phenol ether, that will just stay as phenol, it won't go on to become an alkyl hide. But either way it doesn't matter because we have no halogens anywhere. So choice A H pr cannot be correct because there's no bromine in our products. So what do our products have? Well, again, we've broken the bond and now each of the carbons or the, one of the carbons. So on the toluene that carbon now has hydrogens and on my alcohol, the oxygen that was in ether has a hydrogen. So we've added hydrogens and cleaved the bond we've undergone hydrolysis. So we should be looking for some hydrogen gas and we see it right there in choice C where we have hydrogen gas and a palladium catalyst. So this, we would expect to be our correct answer to be thorough. Let's look at our other answer. Choices. But again, remembering there's really not too many ways that ethers react. In choice B we have sodium hydroxide that base and carbon dioxide. Well, what this might make us think of is the Colby process. But in that case, you react a phenol with sodium hydroxide and carbon dioxide. However, a fennel ether will not react this way since it doesn't have a hydrogen to be removed by sodium hydroxide. That's the first step in the coby process. The hydrogen is removed to generate a pin oxide ion. But our ether doesn't have hydrogen, it can't undergo this reaction. So choice B is not correct as phenyl ether will not react in that way. And then finally, in choice D we have this magnesium metal and carbon dioxide process. Well, that might make us think of the reaction that produces a gra yard reagent. As we recall. Those of those are MGX where X is a halogen. And when you react in alkyl Halide with magnesium in an ether solvent, you generate granard reagent which can then react with carbon dioxide to produce a carboxylic acid. But first of all, we don't have a carboxylic acid, we have an alcohol. So it's not the right product. But more importantly in that reaction, the ether is used as just a solvent precisely because it won't react and it's inert in that case. So Ether has no reaction in that case. So again, it's meant to confuse us a little bit because we might kind of cling on to that ether. But again, in that reaction, the e ether is just being used precisely for its non reactivity. So that's why choice d would not be our answer choice. So once again, the rage that we would need to complete this particular reaction, the hydrolysis of our ether is choice CH two and P DC. See you in the next video.

Suggest the reagents used to effect the transformations shown.
(c)

Key Concepts

Ether Cleavage

Acidic Conditions

Phenol Formation

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