When 2-methylpropene reacts with water and an acid catalyst, only one product alcohol is observed: tert-butyl alcohol (2-methyl-2-propanol).
a. Draw the structures of the two intermediate carbocations that could form from the protonation of 2-methylpropene. Which is more stable (has lower energy)? (Hint: See eq. 3.21.)
b. Draw a reaction energy diagram for the formation of the two intermediate carbocations in 3.45a from protonation of 2-methylpropene. Use your diagram to explain why only one alcohol is formed (see Figure 3.11).