Question

Acid-catalyzed dehydration of secondary and tertiary alcohols proceeds through an E1 mechanism. The first step is the protonation of alcohol and oxygen to form anoxonium ion.

Dehydration of 3-methyl-2-butanol forms one major and two minor organic products. Draw the structures, including hydrogen atoms, of the three organic products ofthis reaction.

The 3.) is correct that is the minor product I came up with but I cant get the answer correct for 1.) major product? and 2.) minor product

Answer 1

Answer 2

Answer 3

Since this is an E1 mechanism, it can be viewed as taking place in two steps: ionization and deprotonation. The first step is shown; the alcohol takes a proton from hydronium, creating a good leaving group. Once it leaves, you have the following: For deprotonation, the H to leave can come from the primary methyl group on the right, or the tertiary carbon on the left. That should make your two remaining products.

As to primary/secondary, the methyl group is more exposed to nucleophilic attack on protons, so the elminiation from the right should be the main product, though the elimination from the left would be the thermodynamic product of reaction.