Hydration of 3-phenylbut-1-ene in dilute `H_(3)SO_(4)` forms 2-pheylbutan -2-ol and not 3-phenylbutan-2-ol. Why ?

Answer

`H_(2)C=CH-underset(Ph)underset(|)CH-CH_(3)overset(H^(+))rarrH_(3)C-overset(+)CH-underset(Ph)underset(|)CH-CH_(3)overset(-H)rarrH_(3)C-CH_(2)-underset(Ph)overset(+)C-CH_(3)`
`underset(-H^(+))overset(H_(2)O)rarrCH_(3)CH_(2)-underset(Ph)underset(|)overset(OH)overset(|)C-CH_(3)`
(Hydration gives an intermediate `2^(@)C`, which undergoes a hydride shift Although phenyl is a better migrator than `H`, migration of H oC Curs leading to a more stable `3^(@)` benzylic carbocation.)