Chapter 8.6, Problem 8P

Instead of the three-step process of Mechanism 8.3, the following two-step mechanism might be considered:

1.

2.

This mechanism cannot be correct! What is its fundamental flaw?

Mechanism 8.3

Acid-catalyzed Hydration of $\text{2-methylpropene}$

The Overall Reaction

The Mechanism:

Step 1: Protonation of the carbon–carbon double bond in the direction that leads to the more stable carbocation:

Step 2: Water acts as a nucleophile to capture $\text{tert-butyl cation}$:s

Step 3: Deprotonation of $\text{tert-butyloxonium ion}$. Water acts as a Bronsted base: