Hydrocarbons Question 135
Question: When 3, 3-dimethyl-2-butanol is heated with $ H_2SO_4 $ the major product obtained is [CBSE PMT 1995]
Options:
A) cis and trans isomers of 2, 3-dimethyl-2-butene
B) 3, 3-dimethyl-1-butene
C) 2, 3-dimethyl-2-butene
D) 2, 3-dimethyl-1-butene
Show Answer
Answer:
Correct Answer: C
Solution:
$ \underset{OHCH_3}{\mathop{\underset{||}{\mathop{\overset{CH_3}{\mathop{\overset{|}{\mathop{CH_3-CH-C-CH_3}}}}}}}}\xrightarrow{H_2SO_4} $
$ \underset{{2^{o}}carboniumion}{\mathop{CH_3-\overset{+}{\mathop{C}}H-\underset{\underset{CH_3}{\mathop{|}}}{\overset{\overset{CH_3}{\mathop{|}}}{\mathop{C-CH_3+O{H^{-}}}}}\underset{Rearrangement}{\mathop{\xrightarrow{\text{Methyl shift}}}}}} $
$ \underset{\begin{smallmatrix} \text{2,3}-dimethyl-2-Butene \\ [MostsynnetrialStructure] \end{smallmatrix}}{\mathop{CH_3-\overset{\overset{CH_3}{\mathop{|}}}{\mathop{C=}}\overset{\overset{CH_3}{\mathop{|}}}{\mathop{C-CH_3}}}}\xleftarrow[-{H^{+}}]{} $
$ \underset{{3^{o}}Carboniumion( Morestable )}{\mathop{CH_3-\overset{\overset{CH_3}{\mathop{|}}}{\mathop{CH-}}\overset{\overset{CH_3}{\mathop{|}}}{\mathop{\underset{+}{\mathop{C-}}}}CH_3}} $
BETA
