Explain the following reaction .

Why `(A)` mainy give `(B)(1^(@)` alcohol `)`, while `(C)` mainly gives `(D)^(2^(@)` alcohol `)` ?

Explanation

Electron `-` withdrawing effect of `CH_(2)Br` makes `2^(@) C^(o+)` less stable , hence, the attack of `H_(2) ddot(O):` takes place on the carbon `(C^(a))`

In propene `(C)`, the electron`-` donating effect of the `(Me)` group stabilises the `2^(@)C^(o+)` and the attack of `H_(2)ddot(O):`takes place on `C^(a)`, so `Br` attaches itself to the terminal position.