[Dynamo22]

When reacting H2SO4 with hept-6-en-2-ol, what products can you form? I know you can form the epoxide 2,6-dimethyloxolane. Our professor wants us to be able to form another product with the same molecular formula of C7H14O. I have tried to figure this out for a while and I can't come up with anything. I don't know how you would form another ring structure or a ketone out of that. Any help would be very much appreciated. I can post a picture of the reaction I have in order to give a better idea if anyone needs that. Thanks!

[discodermolide]

When reacting H2SO4 with hept-6-en-2-ol, what products can you form? I know you can form the epoxide 2,6-dimethyloxolane. Our professor wants us to be able to form another product with the same molecular formula of C7H14O. I have tried to figure this out for a while and I can't come up with anything. I don't know how you would form another ring structure or a ketone out of that. Any help would be very much appreciated. I can post a picture of the reaction I have in order to give a better idea if anyone needs that. Thanks!

The compound you get is not an epoxide but a tetrahydropyran.
Another compound that could be formed is the 7 membered ring, this in small quantities.

[Dynamo22]

Thanks for the correction and reply. Do you think that these two products would be the only products formed with the H2SO4 reagent? I honestly can't think of a reasonable mechanism to form any another product.

[discodermolide]

Thanks for the correction and reply. Do you think that these two products would be the only products formed with the H2SO4 reagent? I honestly can't think of a reasonable mechanism to form any another product.

To give compounds with that molecular formula? Then I can't think of any more.

[Dynamo22]

Great! Thanks so much I appreciate it.

[curiouscat]

Probably a silly question; but how come H2SO4 doesn't dehydrate it to form a diene or hydrate it to form a diol?

[orgopete]

Probably a silly question; but how come H2SO4 doesn't dehydrate it to form a diene or hydrate it to form a diol?

I don't think this is silly at all. It is right on target. Alcohol and ether oxygen atoms are more basic than an alkene. I presume that is why it is difficult to hydrate very weakly activated alkenes, e.g., ethylene and propene. It is easier to add acetic acid to an alkene as the acetate product is less basic.

I was reluctant to suggest an answer for this question as I found it difficult to predict all that would happen. Two products or is it suggest two products that would have a MF of C7H14O? I surmise this is a hypothetical problem as the acid catalyzed addition of water to propene is difficult and in this example, it also has a monosubstituted alkene.

The two products expected are probably the diastereomers of the 2,6-dimethyloxane, cis and trans. I predict if this reaction were performed in the lab, the tetrahydrofurans would also be present.

[curiouscat]

Thank you! What about dehydration of the OH part to another double bond via an elimination? Or are we assuming that the H2SO4 is not conc. enough?

[orgopete]

Thank you! What about dehydration of the OH part to another double bond via an elimination? Or are we assuming that the H2SO4 is not conc. enough?

Dehydration and re-additon would lead to a tetrahydrofuran. I would expect that as well, but now we are over two products with C7H14O.

Again, I am considering this as a hypothetical reaction. You can look up conditions for addition to a terminal alkene and compare them to dehydration of a secondary alcohol. McMurry tells us that propene forms via a bisulfate ester which is then hydrolyzed to an alcohol. That sounds like pretty acidic conditions. I'd be surprised if you dumped this into conc H2SO4 that dehydration wouldn't occur. I don't know whether addition will occur with dilute acid, otherwise why would McMurry report formation of a bisulfate ester.

What we need now is someone with real knowledge.