In the following reaction [figure] The major product is
- [figure]
- [figure]
- [figure]
- [figure]
Answer
(1) [figure]
Solution
Protonation gives a 2° carbocation, which rearranges by 1,2-methyl shift into a more stable 3° carbocation:
(CH3)3C-CH=CH2 H+(CH3)3C- CH-CH3 (2°)
1,2-methyl shift (CH3)2 C-CH(CH3)2 (3°)
H2O, -H+(CH3)2C(OH)-CH(CH3)2
Major product A = 2,3-dimethylbutan-2-ol; the minor product B, (CH3)3C-CH(OH)-CH3, comes from the unrearranged 2° carbocation.
Answer: (1)