When benzene is heated with 3,3 -dimethylbut- 1 -ene in the presence of HF , the major organic product formed is:

Step-by-step solution

Protonation of the double bond in 3,3 -dimethylbut- 1 -ene by HF follows Markovnikov's rule, initially forming a secondary carbocation ( 3,3 -dimethylbutan- 2 -yl cation). This secondary carbocation is adjacent to a quaternary carbon, so it undergoes a rapid 1,2 -methyl shift to form a more stable tertiary carbocation ( 2,3 -dimethylbutan- 2 -yl cation). Benzene then acts as a nucleophile and undergoes electrophilic aromatic substitution with this rearranged tertiary carbocation. The final major product is 2,3 -dim