Question

• A. CH₃ CH₂ CH₂ CH₃
• B. CH₃ CH₂ CH₂ CH₃ and CH₃ CH₃
• C. CH₃ CH₂ CH₂ CH_{3 ,} CH₃ CH₃ CH₂₌ CH₂
• D. CH₃ CH₂ CH₂ CH₃ and CH₂₌ CH₂

Answer 1

The correct option is C

CH₃ CH₂ CH₂ CH_{3 ,} CH₃ CH₃ CH₂₌ CH₂

$R-Br\stackrel{Mg/ether}{\to }R-MgBr\stackrel{D_{2}O}{\to }C{H}_{3}C{H}_{2}D\left(givendata\right)$

But R - MgBr $\stackrel{D_{2}O}{\to }$ R - D

Hence $R=C{H}_{3}C{H}_2$ - or ethyl group

$C{H}_{3}C{H}_{2}Br+2a+BrC{H}_{2}C{H}_3\underset{Ether}{\overset{Dry}{\to }}C{H}_{3}C{H}_{2}C{H}_{2}C{H}_3$ n-butane (Major)

$Na---\to N{a}^{+}+e^{-}$

$C{H}_{3}C{H}_2\stackrel{\curvearrowright }{-}Br+e^{-}⟶C{H}_3{H}_2+B{r}^{-}$

$C{H}_3\stackrel{\cdot }{C}{H}_2+\stackrel{\cdot }{C}{H}_{2}C{H}_3⟶C{H}_{3}C{H}_{2}C{H}_{2}C{H}_3$ (Major product)

Ans c

Note the last step shown is a disproportionation reaction.