Identify the set of reagents/ reaction condition ‘X’ and ‘Y’ in the following set of transformations :
`CH_(3)-CH_(2)-CH_(2)Br overset(X)to "Product" overset(Y)to CH_(3)-underset(Br)underset(|)CH-CH_(3)`

Options

A. `(X)` = Dilute aqueosu `NaOH, 20^(@)C`
`(Y) = HBr//"acetic"` acid, `20^(@)C`
B. `(X)` = Concentrated alcholic `NaOH, 80^(@)C`
`(Y) = HBr//"acetic"` acid, `20^(@)C`
C. `(X)` =Dilue aqueous `NaOH, 20^(@)C`
`(Y) = Br_(2)//CHCl_(3), 0^()c`
D. `(X)` = Concentrateed alcoholic `NaOH, 80^(@)C`
`(Y) = Br_(2)//CHCl_(3), 0^()c`

Answer

`b`

Explanation

`RX overset(X)(rarr) "Alkene" overset(Y)(rarr) "Isomer of RX"`
For `X`, the conditions given are:
`{:(a,b,c,d),(Dil.aq.,Conc. Alcoholic,Dil.aq.,Conc. Alcoholic),(NaOH,NaOH,NaOH,NaOH),(20^@C,80^@C,20^@C,80^@):}`
So conditions (a) and (c) are same and not required becuase in aq. `NAOH. SN^(2)` reaction will occur to give `ROH`.
[So condtions for `E2` elimination is conc. alcoholic
`NaOH` at `80^(@)C` (Conditions (b) and (d) are same.)]
For `Y` conditions given are:
`{:(a,b,c,d),(HBr//"acetic".,HBr//"acetic",Br_(2)//CHCl_(3),Br_(2)//CHCl_(3)),("acid","acid",,),(at20^@C,at20^@C,at0^@C,at0^@):}`
Conditions (c) and (d) are not required becuase they do not give the desired product.
Only condition for `(Y)` is `(a)` or `(b)`
But for `(X)` is as in `(b)`, and condition for `(Y)` as in `(b)`.