When 3-methylbutan-2-ol undergoes a dehydration reaction, the product will be?

Question

1. 3-methylbutanal
2. 3-methylbut-1-ene
3. 2,3-dimethylbutane
4. 3-methylbutan-2-one
5. 3-methylbutanoic acid

Answer 1

When 3-methylbutan-2-ol undergoes a dehydration reaction, the -OH group will leave and a double bold will be formed in order to keep the molecule at a neutral charge.

The double bond can either be formed between C1 and C2, producing 3-methylbut-1-en, OR between C2 and C3, producing 3-methylbut-2-ene.

While the second option would be a more stable product, from the answer choices provided the best answer is 3-methylbut-1-en.

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Answer 2

I am pretty sure that there must be a typo because the secondary carbon in the butane chain would be far better suited to have its double bond shared the third carbon in the chain to create a pi-bond, not the first.

It would be too unstable, and I don't believe it has any chance of forming in the reaction above. I also believe it must be assumed that there's enough heat in the reaction to dehydrate the organic compound because otherwise, it would form an ether compound (carbons on either side of a central oxygen atom).

Thus, the correct answer should be 2. with the typing correction change that it should be:

3-methylbut-2-ene and NOT 3-methylbut-1-ene

I hope this helps! Please message me in the comments if you have any questions, comments, or concerns!