Question

a) Explain mechanistically (with words and equations) how the experimentally observed products are produced from 2-methyl-2-propanol. b) Compare the ratio of products obtained from 2-methyl-2-propanol with those formed from 2-methyl-1-propanol. Propose a mechanistic explanation (words and equations) for these results that is consistent with the computational results for the relative stability of the carbocations and alkenes. Explain your reasoning.

Answer 1

i) In the case of the first reaction using 2-methyl-2-propanol, only one carbocation intermediate is formed, which is a stable tertiary carbocation. As a result, there will be a single product (t-butyl bromide).

ii) In the case of the second reaction using 2-methyl-1-propanol, there will be the formation of two carbocation intermediates, which are the least stable primary carbocation (pathway I) and the most stable tertiary carbocation (pathway II). As a result, there will be the formation of two products (t-butyl bromide as a major product and isobutyl bromide as a minor product).