Question

What ketones would be formed from the acid-catalyzed hydration of 3-heptyne?

Answer 1

You would get heptan-3-one and heptan-4-one.

The acid-catalyzed hydration of a symmetrical alkyne gives a ketone.

R-C≡C-R + H₂O → R-CH₂-CO-R

If the alkyne is unsymmetrical, you get a mixture of two ketones, because the O can add to either of the alkyne C atoms.

R-C≡C-R' + H₂O → R-CH₂-CO-R' + R-CO-CH₂-R'

So, for CH₃CH₂CH₂-C≡C-CH₂CH₃, the products are

CH₃CH₂CH₂-CH₂-CO-CH₂CH₃ and CH₃CH₂CH₂-CO-CH₂-CH₂CH₃

Their names are heptan-3-one and heptan-4-one,