Consider the following sequence of reactions

How many structures of `[A]`are possible?

Options

A. `6`
B. `5`
C. `2`
D. `3`

Answer

D

Explanation

`CH_(3)-CH_(2)underset(OH)underset(|)(CH)CH_(3)overset(H^(+))underset(-H_(2)O)rarrCH_(3)underset((I))underset(But-1-en)(CH_(2)CH=CH_(2))`

Order of yield is `III gt II gtI`
Addition of `Br_(2)` to an alkene is an antio addition:

`CH_(3)CH_(2)CH=CH_(2)overset(Br_(2))rarrunderset("racemic mixture of enantiomers")underset(Br)underset(|)overset(**)(CH_(3)CH_(2)CHCH_(2)Br`
Thus, we get a total of five products of formula `C_(4)H_(8)Br_(2)`.